Mcat (Biology)

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Conversions (cm, mm, um, A)

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1 cm - 10mm
1 mm - 1000 um
1 um - 10,000 A (angstrom unit)

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Resolution

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is commonly defined as the ability to discriminate two points and visualize them as two points, even though that are extremely close together.

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Composition of Protoplasm (Contents of Living Cells)

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protoplasm is mode up mainly of proteins, carbohydrates, fats, salts, and water.
Oxygen 75+%
Carbon 10+%
Hydrogen 10+%
Nitrogen 2+%
Sulfur 0.2%
Phosphorus 0.3 %
Potassium 0.3%
Chlorine 0.1%
less than 0.1% - sodium, calcium, magnesium, iron, ect.

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Plasma membrane

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Also known as plasmalemma, which serves as the permeability barrier between the cell and its enivornment

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lipid bilayers

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what makes up the plasma membrane. the lipid bilayers consist of two phospholipid layers in which globular proteins float about.

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Oligosaccharide groups

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(polymers of sugars) attached to proteins and lipids. The oligosaccharide bearing components are especially numerous on the external surface of the plasma membrane.

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Glycerophospholipids

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Contain a glycerol linked to two fatty acyl groups and one phosphate group.
The phosphate group may in turn be linked to further groups such as ethanolamine, choline, serine, or inositol.

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Sphingolipids

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contains a sphingosine linked to one fatty acyl group and are usually linked to a phophate plus a choline (sphingomyelin), a sugar (ceramides), or to a complex oligosaccharide (gangliosides). sphingolipids are absent from most prokaryotes and occur primarily in the outer face of the plasma membrane in eukaryotes.

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Lysophospholipids

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have one fatty acyl group removed, cutting the ratio of nonpolar to polar structure in half.

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Peripheral membrane proteins

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are attached to integral membrane components (lipids or proteins) by noncovalent bonds. Peripheral proteins may be removed from a membrane by milder treatments than are required to remove integral membrane proteins.

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Integral membrane proteins

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cannot be released from a membrane without breaking covalent bonds or disrupting the lipid bilayer.
Some integral membrane proteins are anchored to the lipid bilayer by covalent linkage to a lipid, usually a fatty acyl group (frequently a myristyl group), a prenyl group (frequently a farnesyl group), or a phospholipid (usually a glycosylphosphatidylinositol [GPI] anchor).

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Transmembrane integral membrane proteins

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contain one or more protein domains that extend across the lipid bilayer. Most ransmembrane domains appear to adopt alpha helical secondary structure and consist primarily of amino acids with hydrophobic side chains.
Some form ion channels across the membrane, others are active transport or facilitated diffusion carriers, and still others are receptors for growth factors or hormones

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Concentration Gradients

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consisting of differences in concentration of a component in a fluid can drive a net movement of that component. Each component in any fluid will diffuse from regions of high concentrations of that component toward regions of low concentration of that component. This movement, is called simple diffusion, is the result of random movements of each particle in the fluid, and occurs whether the component is charged or not.

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Electrostatic gradients (potential fields)

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can drive net movements of charged particles such as ions in a fluid. Charged components in a fluid will be attracted to opposite charges and repelled by similar charges. Therefore, if a potential field is present, positively charged particles will move toward the negative pole and negatively charged particles will move toward the positive pole.

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How do very small molecules (no net charge) get across the lipid bilayer membrane?
Name Examples

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Examples: Water, oxygen, carbon dioxide
They get by relatively easily by simple diffusion, regardless of the polarity of the molecules. These molecules do not require carriers or channels to cross membranes.

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How do non polar molecules with no net charge cross bilayer?
Name Example

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Examples: Moderate - Benzene, steroids
These molecules have much more trouble moving through the water to get to the membrane than they have crossing the membrane
Large - fatty acids or trigylcerides
may primarily move through blood or tissue fluid complexed with lipoprotein and may be taken up by cells through a receptor-mediated endocytosis mechanism that recognizes the protein component of the lipoprotein and takes up the lipid along with the protein.

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How do polar molecules get through the bilayer?

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Polar molecules up though 3 carbons in size and with no net charges cross bilayers moderately rapidly. These molecules usually cross membranes without requiring channels or carriers.
Polar molecules in the size range of biological monomers (5 &6 carbon sugars) and with no net charge cross lipid bilayers very slowly, usually too slowly to support metabolic processes. These molecules must therefore cross membranes by way of a channel or by way of a carrier-mediated mechanism.

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How do ions and polar macromolecules get through the bilayer?

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They cross is very slowly, if at all. These ions or molecules must therefore cross membranes by way of a channel or by way of a carrier-mediated mechanism. Many types of macromolecules may initially be taken into cells through receptor-mediated endocytosis, then cross the membrane of the vesicle formed during endocytosis after alteration of the macromolecule.

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Define Osmosis, hypotonic, hypertonic, isotonic

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is a special case of simple diffusion. It is the diffusion of water in a cell. Water diffuses from areas of lower solute concentration to areas of higher solute concentrations.
hypotonic - is lower solute concentration, therefore higher water concentration
hypertonic - higher solute concentration, therefore lower water concentration
isotonic- same total solute concentration as inside the cells (multicellular animal cells normally operate like this)

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Name all the Passive Transport

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Simple diffusion
Osmosis (a special case of simple diffusion)
Facilitated diffusion

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Name all Energy-requiring transport

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Active Transport - a protein carrier moves the particle independently of its electrochemical gradient, the carrier consumes energy (usually ATP)
Endocytosis - Process whereby the cell membrane engulfs extracellular material, moves it into the cell, and forms membrane-bound vesicles.
Exocytosis - Manufactured and modified materials are secreted by this process and eliminated from the cell.

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Facilitated Diffusion

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A channel or uniporter carrier (both usually proteins) the movement is down the component's electrochemical gradient and shows saturation kinetics.

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Difference from Facilitate diffusion and active transport

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Active transport is
1. sensitive to the concentration of the component on only one side of the membrane (the "loading" side,
2. insensitive to the concentration of the component on the other side of the membrane, and
3. usually saturates at relatively low component concentrations

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Define Secondary Active Transport, symport, antiport

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Secondary Active Transport - once a reliable concentration gradient of one component has been established by active transport, its concentration gradient may in turn be used to drive additional coupled active transport mechanisms
Symport - if the couple component moves in the same direction as the gradient component
Antiport - if they move in the opposite direction

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Define Prokaryotic Cells
(structure also)

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they have no nuclear envelope separating the nuclear material from the cytoplasm. Organisms with prokaryotic cellular structure are unicellular, so each cell is an organism. Prokaryotic organisms frequently occur in loosely organized colonies.
A typical prokaryotic cell consists of a nuclear area or nucleoid surrounded by cytoplasm. The cytoplasm is bounded by a plasma membrane, which is in turn typically surrounded by a cell wall complex.

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Define Eukaryotic Cells

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They contain a nuclear envelope that separates their nuclear compartment from their cytoplasmic compartment. Organisms with eukaryotic cellular structure may be unicellular (protistans) or multicellular (fungi, plants, and animals). Multicellular eukaryotes contain multiple cell types in organized patterns.

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Define Free Ribosomes in Prokaryotic Cells

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they appear scattered in the cytoplasm as more darkly stained granules of approximately 25 nm (250 A) diameter. All of the proteins made in prokaryotic cells are made on free ribosomes

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Nuclear Area in Prokaryotic Cell

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It consists of circular DNA molecule anchored at one location to the plasma membrane, but which is otherwise free in the cytoplasm.
Prokaryotic DNA is not organized into the nucleosomal histone-DNA complexes typical of eukaryotic nuclear DNA.
The DNA in the nuclear area contains most of the genetic information in a prokaryotic cell, although smaller episomes or plasmids may also be present in the cell. Plasmids frequently contain genes conferring resistance to antibiotics.

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Membranous Structures in Prokaryotic Cells

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are normally absent from the cytoplasm of most prokaryotic cells.
These internal membranes derived from the plasma membrane and occur in cyanobacteria and some other photosynthetic bacteria.
These membranes are sometimes called chromatophores, contain the photosynthetic pigments and function like the thylakoid membranes in chloroplast.

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Plasma Membrane of a Prokaryotic Cell

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Consists of a typical phospholipid bilayer with embedded and surface associated proteins.
The plasma membrane of a prokaryotic cell lacks glycolipids and cholesterol, which are typically found in eukaryotic plasma membranes.
The plasma membrane appears to be the major structure controlling movement of molecules in and out of prokaryotic cells

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Cell Wall complex in Prokaryotic Cell

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is usally prosent outside the plasma membrane in most prokaryotic cells. The cell wall complex differs strikingly between Gram-positive and Gram-negative bacteria

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Gram-positive bacteria

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Have a cell wall consisting of a thick layer of peptidogylcans, which consist of sugars and amino acids. This cell wall supports and protects the individual cell that it surrounds.

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Gram-negative bacteria

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are surrounded by a more complex wall structure consisting of a thin layer of peptidoglycans surrounded by an "outer membrane" of lipopolysaccharide and protein.
Channel-forming proteins called porins allow selected molecules to cross the outer membrane.
A fluid-filled periplasmic space containing enzymes lies between the two membranes

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Flagella in Prokaryotic Cells

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They may have structures extending outward from the cell wall complex.
Flagella consist of a protein rod (about 1/10 as thick as eukaryotic flagellum and lacking microtubules in its core) attached to the cell by a hook (bent structure) and a swivel (basal rotational mechanism. Flagella are responsible for the movement of the cell

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Pili in Prokaryotic Cells

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are hollow protein tubes that attach bacteria to surfaces and transfer DNA between cells during conjugation (mating).

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Capsule or slime layer in prokaryotic cell

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My prokaryotic cells have this consisting of a loose polysaccharide gel located outside the cell wall complex. This layer protects parasitic bacteria against host defense mechanisms.

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Nuclear Envelope in Eukaryotic Cell

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The nuclear compartment (nucleus) is separated from the cytoplasmic compartment by a nuclear envelope consisting of two layers of membrane and perforated by nuclear pores.
The outer membrane is chemically similar to endoplasmic reticulum.
The inner nuclear membrane has inserted proteins that connect with the nuclear lamina (containing intermediate filament-like lamin proteins), which in turn connects to the nuclear matrix.

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Nuclear Pores in Eukaryotic Cell

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these help the nuclear contents (nucleoplasm) to exchange materials with the cytoplasmic contents (cytosol) by diffusion and selective transport.

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Nucleolus in Eukaryotic Cells

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which is visible in most eukaryotic cell nuclei during interphase, contains small amounts of DNA and larger amounts of RNA (mostly rRNA) and proteins.
The nucleolus is the location of rRNA synthesis and assembly of ribosomal subunits from rRNA and from proteins imported from the cytoplasm.

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Chromosomes in Eukaryotic Cells

What are the three essential components of functional eukaryotic chromosomes?

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This is how nuclear DNA is organized.
Species will have Chromosome number, shape of the condensed chromosomes during mitosis and meiosis, and DNA content of each chromosome are consistent among the normal members of species.

The three essential components are 1. centromere sequence
2. replication initiation sequence (isolated replication initiation sequences are referred to as autonomously replicating sequences.
3. Telomere sequence (at the end to prevent the loss of genetically critical sequences.)

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Chromatin in Eukaryotic Cells

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Unreplicated eukaryotic chromosomes that contains a single linear DNA molecule which is complexed with protiens. The weight ratio of protein to DNA is approximately 2:1 by weight.

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Histones in Eukaryotic Cells

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are the most numerous category of proteins in chromatin, comprising approximately half of the chromatin protein and occurring in apporx. a 1:1 ratio to DNA by weight. Histones contain numerous amino acids with side chains containing basic functional groups, resulting in a net positive surface charge which binds ionicaly to the negatively charged phosphate groups in DNA.

Class H1 (H5 in some cells) bind to the DNA between closely spaced nucleosomes to aggregate the DNA into 30nm diameter chromatic fibers

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Nucleosomes in Eukaryotic Cells

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They consist of histone classes H2A, H2b, H3, and H4 aggregate with DNA.
Nucleosomes appear to form at close spacing on most chromosomal DNA regions unless nucleosome assembly is inhibited by regulatory proteins bound to the DNA.

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Define euchromatin and heterochromatin

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Euchromatin - when viewed by light and electron microscopy it is the extensive regions of DNA between nucleosomes (DNA that are transcriptionally active). They appear in a lighter stain

Heterochromatin - the chromatic fibers that are created by histones (H1 or H5) (see Histones)

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Cytosol in Eukaryotic Cytoplasm

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The largest functional compartment in eukaryotic animal cells. Also called known as fluid cytoplasm between recognizable cytoplasmic organelles.
The cytosol consists primarily of moderately dark -staining material containing proteins, other macromolecules, small molecules, ions, and water.
Glycolysis and many other general metabolic processes occur in the cytosol

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Free Ribosomes in Eukaryotic Cytoplasm

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These organelles appear scattered in the cytosol as more darkly stained granules. All the proteins that will function in the cytosol, nucleus, and peroxisomes are made on free ribosomes.
Free ribosomes that are engaged in protein synthesis are organized into polyribosomes which may appear as clusters, linear arrays, or rosettes.

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Smooth endoplasmic reticulum (ER)

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The organelle consists of irregular tubes and flattened sacs or cisterni of cytoplasmic membrane and has no ribosomes on its cytoplasmic surfaces.
ER (both) provides the surfaces on which synthesis of phospholipids and part of the synthesis of steroids occurs.
Enzymes associated with sER are also involved in detoxify many foreign molecules such as drugs.

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Secretion and Endocytosis Apparatus

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This is made up of rER, Golgi bodies, lysosomes, secretory vesicles, and numerous types of transport vesicles may be viewed as an integrated functional system that manufactures, modifies, and moves proteins and other molecules that may be secreted by exocytosis or taken into the cell by endocytosis.

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Rough Endoplasmic Reticulum (rER)

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consists of flattened sacs of cytoplasmic membrane with ribosomes associated with the cytoplasmic surface.
The ribosomes on rER are the site of synthesis of proteins that will be "packaged" by the Golgi bodies. These proteins include lysosomal enzymes and proteins that will be secreted by the cell.

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Golgi Bodies (cis and trans)

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Consist of stacks of flattened sacs of smooth cytoplasmic membrane. The stacks of membrane sacs in a Golgi body is polarized. One surface receives vesicles from the rER called the cis face. The other surface buds off vesicles that carry materials to lysosomes, secretory vesicles, and the plasma membrane (called trans)
In plants the Golgi is called dictyosomes.
In animal cell the golgi is usually located near the pair of centrioles that are found next to the nucleus.

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Secretory vesicles

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These are spherical sacs of membrane containing materials that will be secreted from the cell by exocytosis

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Lysosomes

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These are spherical sacs of membrane-containing hydrolytic enzymes (digestive enzymes) that function in acidic environments (pH 4.5 to 5) Lysosomal enzymes usually function in digestion of material brought into the cell by phagocytosis or in digestion of damaged organelles.

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Mitochondria

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Organelles are approximately 0.5 um in diameter and contain two layers of membrane. The outer membrane is smooth, whereas the inner membrane is folded into finger-like or shelf-like cristae. The fluid in the inner membrane is called the matrix.
Most of the ATP synthesis during aerobic cellular respiration occurs in mitochondria.
The Krebs cycle occurs in the matrix
Electrons are collected by flavin adenine dinucleotide (FAD) or nicotinamide adenine dinucleotide (NAD) and then passed along the electron transport system.
These enzymes are integral membrane proteins in the inner membrane, and generate a proton (hydrogen ion) gradient across the inner membrane which is used as an energy source to convert ADP to ATP.
Mito has its own DNA

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Cytoskeleton types and definition

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Define - consists of the components that alter cell shape and the anchor and move organelles in cells.

Three kinds
1. microfilaments
2. microtubules
3. intermediate filaments

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Microfilaments

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contain action protein subunits assembled into very thin filaments. Microfilaments are usually associated with myosin and other proteins. they are bundled into much larger stress fibers in some cell types. Microfilaments are capable of contraction, usually by sliding past each other due to interaction with myosin or some other "motor" protein

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Mictrotubulees

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Contain alpha and beta tubulin protein subunits assembled into very small tublues. They are ridgid tubes that can support cell shape or serve as a surface along which to move organelles.
They rearranged to form the mitotic spindle during mitotic cell division.

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Intermediate Filaments
Name 5 major ones

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Contain one of a family of intermediate filaments proteins assembled into fibers with a diameter of approx. 10 nm.
1. desmin
2. cytokeratin
3. vimentin
4. neurofilament
5. glial fibrillary acidic protein
They can be bent but resist stretching

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Centrioles

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They are cylinder of 9 triplets of microtubules. They occur in the center of the centrosome region next to the nucleus in animal cells.
they are duplicated and are associated with the ends of the mitotic spindle during mitosis.

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Cytoskeleton - Associated Cell Surface Appendages

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1. Cilia
2. Flagella
3. Microvilli

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Cilia and Flagella

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Both have a core axial structure (axeoneme), which contains a cylinder of nine doublets of microtubules with an additional pair of single microtubules in the center.
They both have an outer covering of plasma membrane
They are both motile

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Microvilli

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These are small finger-like projections of the cell surface. Contain only microfilaments (no microtubules) and cytosol and have an outer covering of plasma membrane.
Microvilli are frequently an adaptation to increase surface area for absorption of solutes.

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Peroxisomes

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The organelles are membrane-lined vesicles that typically contain catalase, which generates hydrogen peroxide used to detoxify various organic molecules.
Also involved in beta oxidation of fatty acids, and are involved in photorespiration and the glyoxylate cycle in plant cells.

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List all Inclusions

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1. Lipid droplets
2. Glycogen granules
3. Melanin granules

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Lipid Droplets

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These are spherical aggregates of lipid. The outer layer may contain phospholipids, a typical membrane structure doesn't appear to separate the lipid droplet from the cytoplasm

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Glycogen Granules

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occur as clusters in cytoplasm. They are larger than ribosomes in routine preparations.

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Melanin Granules

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They are membrane-bound vesicles containing melanin. They occur in cells near the basal layer in epidermis of skin and the pigmented cells at the rear of the retina of the eye.
In epidermal cells they are made in melanocytes and transferred into the epidermal cells

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Plasma Membrane (Eukaryotic)

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also know as plasmalemma, a typical cellular membrane consisting of a lipid bilayer with integral and peripheral proteins.
common features

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Cell-Cell Junctions
List some

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These are structures that join adjacent cells in multicellular animals.
1. Occluding junctions (zonula occludens)
2. Attachment junctions
3. Communicating junctions

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Occluding Junctions

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Also known as Zonula Occludens.
These are regions in which the outer layers of the plasma membranes of associated cells appear fused (no extracellular space).
A zonula occludens complex usually occurs as a band around the apical ends of epithelial cells in a sheet epithelium. They prevent passage of materials through the extracellular space between cells and allow an epithelium to serve as a barrier.

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Attachment Junctions

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Two kinds
1. Zonula Adherens - typically are adjacent to zonula occludens junctions. They form a mechanical attachment between cells, which protects zonula occludens junctions in epithelial cells
2. Macula Aderens - may occur in two forms
a. desmosomes - joining two adjacent cells
b. hemidesmosomes - joining a cell to its basal lamina.

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Communicating junctions

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these allow ions to move from the cytoplasm of one cell to the cytoplasm of an adjacent cell.

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Cell Walls in Eukaryotic Cells

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These structures consist of layer of extracellular material (cellulose, pectins, in higher plants and chitin in fungi.)

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Extracellular Matrix

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The material located around and between cells in multicellular animals is referred to as this.
It contains fibrous proteins or glycoproteins such as collagen and elastin.
EM in bone is hardened by adding calcium and phosphate ions
EM is the major structural component in the connective tissues that give shape to the bodies of most higher animals

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Steps of Mitosis and what they do

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1. Prophase - chromosomes become distinct and nucleolus (nucleoli) disappear(s); centriole(s), and asters and spindle appear: nuclear membrane disappear
2. Metaphase - Chromosomes move to the equator of the cell and duplicate
3. Anaphase - the two chromatids split apart and start migration toward the poles of the spindle; the spindle loses its definition
4. Telophase - Chromosomes lengthen and become less distinct; nucleoli reappear.
5. Interphase - Cell growth; protein synthesis; DNA synthesis; chromosome duplication

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Name the Enzyme that catalyzes the initial replication of the viral genome during infection of a eukaryotic cell by a typical retrovirus

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Reverse Transcriptase

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Bacteriophages

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reproduced only in living bacterial cells
Two pathways
1. lytic replication strategy (pathway)
2. lysogenic strategy (pathway)

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What are the two polymers of nucleotides? And what are they called
List dinucleotides
List single nucleotides

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DNA (deoxyribonucleic acid)
RNA (ribonucleic acid)
these are called nucleic acids

Dinucleotides
FAD, NAD, NADP

Single Nucleotides
ATP, CTP, GTP, AND UTP

Front 78

Nucleotides are monomers that are assembled to produce more complex nucleic acids. Each nucleotide consists of what three components?

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1. Pentose Sugar. one five-carbon sugar that is either ribose (ATP, FAD, NAD, NADP, and RNA) or deoxyribose (DNA).
2. Nitrogenous Base - one base that is either a purine or pyrimidine.
Pyrimidine - consist of a 6-membered ring containing carbon and nitrogen atoms. (Cytosine, Uracil, and Thymine)
Purines consis of a similar 6-membered ring fused to a 5-member ring (Adenine, Guanine)
Phosphate - one (MP), two (DP), or three (TP) phosphate groups. The letter code for the nitrogenous base plus the number of phosphates can be used to designate a nucleotide. For example, a nucleotide with adenine and one phosphate is AMP.

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Where is energy stored in nucleotides?

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where there are more then one phosphates the extra (second and third) phosphates to the nucleotide are less stable and can be easily hydrolyzed to release the energy used to make those bonds and make that energy available to other processes in the cell.
This makes triphosphates (TP) the primary energy source used to supply energy-consuming reactions in cells.

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Where is ATP, UTP, GTP used?

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ATP is the most widely used nucleotide triphosphate and is used for a wide variety of reactions
UTP- is used in biosynthetic reactions involving additions of sugars.
GTP- is used to provide energy for protein shape changes by G proteins involved in receptor-triggered reaction sequences and protein synthesis

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Nomenclature of Nucleotides

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1. The base (pruine or pyrimidine) is attached to the 1' carbon on the sugar
2. The phosphate group is attached to the 5' carbon on the sugar.
3. The hydroxyl group on the 3' carbon on the sugar is reacted with the phosphate group on the adjacent nucleotide is added to a DNA or RNA chain.

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What are the base pairs?
What type of bond do they form?
How many bonds do that form?

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Adenine base pairs with uracil (RNA) or thymine (DNA) by forming two hydrogen bonds.

Guanine base pairs with cytosine by forming three hydrogen bonds

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How does RNA usually occur?

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Consists of a single linear chain of nucleotides. However, RNA chains may fold and form base pairs between regions of the same chain where complementary sequences occur, resulting in "hairpin" loops. Double-stranded RNA occurs as the genetic material in some viruses.

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Messenger RNA

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mRNA codes for the amino acid sequence (primary structure) of polypeptide chains in proteins.

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Transfer RNA

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tRNA carries amino acids (as aminoacyl groups on the tRNA) into protein synthesis and uses the nucleotides sequence in a mRNA to determine where to insert the amino acid carried by the tRNA into the forming polypeptide chain. The amino acid-RNA linkage in the aminoacyl tRNA is formed using energy from nucleotide triphosphates and contains the energy needed to form the peptide bond joining the amino acid to the peptide.

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Ribosomal RNA

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rRNA form the structural framework of the ribosomal subunits, and a loop of one of the rRNA molecules appears to be capable of catalyzing the formation of peptide bonds.

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Small nuclear ribonucleoproteins

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snRNPs contain small RNA molecules that remove introns from mRNA in eukaryotes.

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Genotype

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Genetic information that is stored in cells in the form of the sequence of deoxyribonucleotides in DNA.

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Transcription

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RNA synthesis - the deoxyribonucleotide sequence in regions of DNA (genes) codes for (serves as a template) the ribonucleotide sequence in mRNAs. The bases in RNA can hydrogen bond to the bases in DNA, so one base in DNA specifies one base (complementary to it) in RNA

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Translation

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Protein Synthesis - the ribonucleotide sequence in regions of DNA (genes) codes for the ribonucleotide sequence in mRNAs codes for the amino acid sequence in proteins (polypeptides). A three nucleotide codon in mRNA base pairs with the complementary three nucleotide anticodon on an aminoacyl tRNAto allow the aminoacyl group (one amino acid) on the aminoacyl tRNA to be added to the polypeptide (protein) being synthesized.

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Phenotype

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consists of the structures and functions of the cell.

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Name and define the 4 functions

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1. structural proteins - form all or parts of cell structures such as ribosomes, chromosomes, mitotic spindles, and cell membrane
2. Enzymes are almost all proteins and are required to catalyze most chemical reactions in cells, including DNA synthesis, RNA synthesis, protein synthesis, carbohydrate synthesis, and lipid synthesis. Most cellular reactions will not occur under normal intracellular conditions without access to the appropriate enzyme
3. Transport proteins - serve as carriers or channels to allow molecules to move across cell membranes to to enter cells, leave cells, or move from one part of a cell to another.
4. Signal or regulatory proteins - respond to changes in a cell by changing their interactions with critical components such as DNA, thereby altering cell functions

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Replisome or Replication Complex in Prokaryotic Cell

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This association of enzymes is a large complex that catalyzes DNA replication once it has begun.

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DNA Helicase in Prokaryotic Cells

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Separates the two strands of the DNA molecule that will be replicated so that each strand can serve as a template for the synthesis of a new strand. ATP is hydrolyzed as the helicase moves along

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Okazaki Fragments

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On the lagging strand. The stand that is lagging behind the leading strand because it is in the opposite direction.

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Name the enzymes used and there functions for the lagging strand in Prokaryotic Cells

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1. Single-strand DNA Binding Protein - binds to and protects single-stranded regions of DNA exposed in the lagging strand
2. DNA Primase - synthesizes a short segment of RNA complementary to the template strand of DNA. The RNA primer is usually about 10 nucleotides after the last primer segment
3. Lagging Strand DNA Polymerase III - adds deoxyribonucleotides to the 3' end of the RNA primer, moving along the template strand until it contacts the 5' end of the next RNA primer. The DNA polymerase then releases the DNA and somehow "leapfrogs" back up the DNA template to the next RNA primer
4. DNA Repair Complex (containing DNA Polymerase I) then treats the RNA primer segments in the same way that the repair complex treats any other structurally abnormal segment of DNA. The abnormal part (the ribonucleotides) are removed and replaced with normal components (DNA)
5. DNA Ligase - then joins the free ends of adjacent sements of the new DNA strand to from a continuous strand.

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DNA Polymerase alpha
DNA Polymerase delta

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alpha - catalyzes the synthesis of the new DNA strand for the lagging strand

delta - catalyzes the synthesis of new DNA for the leading strand

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DNA Polymerase beta
DNA Polymerase gamma

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beta - same in Prokaryotic Cells DNA repair enzyme

gamma - preforms DNA replication in mitochondrial DNA

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Type I topoisomerases

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occur in both prokaryotes and eukaryotes. Although the detailed mechanism differ, these enzymes all temporarily clip on strand of double-stranded DNA to allow untwisting (in both prokaryotes and eukaryotes)

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Type II topoisomerases

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(both E and P) These enzymes cut both strands of one DNA double-stranded helix to allow a second double-stranded helix to pass through. This is used to separate interlocked loops in Pro and in mito. It is bound to nuclear DNA at intervals and may attach DNA to the chromosomal scaffolding as well as to reduce tangling during replication

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Photoreactivation. Pyrimidine Dimers

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produced by ultraviolet light can be repaired by photoreactivation without excision of components. The enzyme that catalyzes the repair is called DNA photolyase or photoreactivating enzyme and is the product of a single gene. The enzyme uses visible light energy to remove the covalent bonds, generated by the UV light. This system is active in many prokaryotes and plants, but is absent in many animals, including humans

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Base Excision Repair

Back 102

Some single damaged nitrogenous bases (especially uracil) can be removed from there deoxyribose by a glycosylase enzyme, after which one or more nucleotides in the damaged area are removed and replaced. This can occur in both pro and euk.

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Nucleotide Excision Repair

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This more generalized process can remove almost any type of damage as long as one of the two DNA strands is undamaged. In this case, a stretch of nucleotides is removed, then replaced by a new strand whose assembly is catalyzed by a DNA polymerase. Methylation of the older DNA strand is the molecule is apparently used to decide which is the preferable template strand when a mismatch occurs without obvious damage. (both pro and euk)

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What enzymes catalyzes transcription in Prokaryotes?

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RNA polymerase (the core enzyme) with multiple sigma factors factors

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Protein-coding DNA (eukaryotes)

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some DNA regions code for functional amino acid sequence-coding regions of mRNA molecules. In most eukaryotic cells, each structural gene coding for the mRNA which is translated into a single polypeptide typically has its own promoter and associated genetic control regions.

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RNA-coding DNA (eukaryotes)

Back 106

Genes that code for structural RNAs typically occur in tandemly repeated units in eukaryotes. Large rRNA molecules are coded by 250 copies of a tandemly repeated cluster.

Front 107

Noncoding DNA (eukaryotes)

Back 107

More then 70% of the DNA sequences in a multicellular eukaryote are no represented in functional mRNA, rRNA, or tRNA molecules in the cytoplasm

Front 108

RNA Polymerase I, II, III

Back 108

I - rRNA

II - mRNA (U1-U5 snRNP)

III - tRNA, (5S rRNA, U6 snRNP)

Front 109

Capping

Back 109

Almost immediately after initiation of transcription, one of the three phosphates on the 5' nucleotide on the RNA is removed and a GMP (derived from a GTP)is attached using a 5'-5' linkage. Methyl groups are then added to the guanine in the terminal position and to the base (usually A or G) on the original 5' terminal nucleotide.

Front 110

Poladenylation

Back 110

Just after RNA polymerase II passes the poly-A addition signal on the DNA, the RNA transcript is cleaved at the signal. Poly-A polymerase then adds 100 to 200 adenosine nucleotides to the 3' end of the transcript to form the poly-A tail. Different patterns of 3' cleavage and poly-A addition may produce different carboxy-terminal ends on the protein and different life spans for the mRNAs in the cytoplasm

Front 111

Intron Removal

Back 111

The snRNPs U1, U2, U5 and U4/U6 plus other components assemble on the recognition sequences on each intron to form a spliceosome.The intron is excised in a loop or lariat form and the adjacent exons are ligated together. In many genes, intron removal may destroy over half of the original transcript. Different patterns of intron removal in different cells types lead to different protein coding sequences in mRNAs produced from identical transcripts.

Front 112

Editing

Back 112

mRNA nucleotide sequence can be changed by editing enzymes that change or delete nucleotides. conversion of single bases has been documented for several human mRNAs, and extensive editing using guide RNAs has been demonstrated in trypanosomes. The full effect and extent of this process is not fully understood.

Front 113

Three things that divide living things into five kingdoms?

Back 113

1. the presence (eukaryotic) or absence (prokaryotic) of membrane-bound nuclei in the cells
2. the number of cells forming the organism
3. the mechanism for nutrition.

Front 114

Name the Five Kingdoms

Back 114

1. Monera
2. Protista
3. Fungi
4. Plantae
5. Animalia

Front 115

Define Monera and give example

Back 115

Unicellular without organized nuclei; absorb or produce their own nutrients

Examples : bacteria, blue-green algae

Front 116

Define Protista and give examples

Back 116

Unicellular with membrane-bound nuclei; ingest, absorb, or produce nutrients via photosynthesis

examples: protozoans, algae

Front 117

Define Fungi and give examples

Back 117

Multicellular with membrane-bound nuclei; absorb nutrients

Example: mushrooms, molds

Front 118

Define Plantae and give examples

Back 118

Multicellular with membrane-bound nuclei and a cell wall; possess chlorophyll and undergo photosynthesis

Example: flowering plants and trees: evergreens

Front 119

Define Animalia and gives examples

Back 119

Multicellular with membrane-bound nuclei; ingest nutrients

Examples: mammals, birds, amphibians, fish, reptiles, insects, crustaceans

Front 120

Classification order

Back 120

Kingdom -> Phylum -> Subphylum -> Class -> Order -> Family -> Genus -> Species

Front 121

Classification of the Human

Back 121

Kingdom - Animalia - consume food by ingestion and are multicellular and usually mobile.

Phylum - Chordata - notochord, hollow nervous system (neural tube) dorsally positioned, gill slits in pharyngeal wall, heart ventral to digestive system

Subphyum - Vertebrata - Segmental vertebral column

Class - Mammalia - Mammary glands for nourishment of young; hair or fur; warm-blooded; diaphragm

Order - Primates - Large cerebral hemispheres; opposable digits; nails; highly developed sense of sight (eyes directed forward); teeth specialized for different functions

Family - Hominidae - Walk with two limbs (bipedal locomotion); binocular color vision

Genus - Homo - Ability to speak and most highly developed and largest brain

Species - sapiens - Large skull, high forehead, reduced size of brow (supraorbital) ridges, prominent chin; decreased amount of body hair

Front 122

Name the Human organ systems

Back 122

1. Muscular
2. Skeletal
3. Circulatory
4. Nervous
5. Integumentary
6. Digestive
7. Respiratory
8. Urinary
9. Reproductive
10. Endocrine

Front 123

Muscular System

Back 123

Produces motion of body parts and viscera

Front 124

Skeletal System

Back 124

Supports the body, protects organs, and produces blood cells

Front 125

Circulatory System

Back 125

Transports nutrients, wastes, gases (oxygen and carbon dioxide) , hormones, blood cells throughout body; also protects body against foreign organisms

Front 126

Nervous System

Back 126

Responds to internal and external stimuli; regulates and coordinates body activities and movements

Front 127

Integumentary System

Back 127

Limits and protects the body as a whole ; prevents excess loss of water and functions in regulating body temperature

Front 128

Digestive System

Back 128

Enzymatically breaks down food materials into usable and absorbable nutrients

Front 129

Respiratory System

Back 129

Functions in the exchange of gases (oxygen and carbon dioxide)

Front 130

Urinary System

Back 130

Removes body wastes from blood stream and helps regulate homeostasis of internal environment

Front 131

Reproductive System

Back 131

Perpetuates the living organism by the production of sex cells (gametes) and future offspring

Front 132

Endocrine System

Back 132

Regulates body growth and function via hormones.

Front 133

Name the three types of muscle tissue?

Back 133

1. Skeletal
2. Smooth
3. Cardiac

Front 134

Characteristics and Location of skeletal muscles

Back 134

They are striated and voluntary

They are located on the skeletal muscles of the body

Front 135

Characteristics and Location of smooth muscles

Back 135

They are nonstriated and involuntary

They are located on the walls of digestive tract and blood vessels, uterus, urinary bladder

Front 136

Characteristics and Location of cardiac muscles

Back 136

They are striated and involuntary

located in the heart

Front 137

Name the characteristics of epithelial tissue.

Back 137

1. has compactly aggregated cells
2. has limited intercellular spaces and substance
3. is avascular (no blood vessels)
4. has a basally located basal lamina usually attached to underlying connective tissue
5. has cells that form sheets and are polarized (have distinct apical and basal surfaces)
6. is derived from all three germ layers

Front 138

Name the 9 types of Epithelial tissue

Back 138

(all end in epithelial)
1. Simple squamous
2. Stratified squamous keratinized
3. Stratified squamous non keratinized
4. Simple cuboidal
5. Stratified cuboidal
6. Simple columnar
7. Pseudostratified columnar
8. Stratified columnar
9. Transitional

Front 139

Simple squamous epithelium

Back 139

Located in endothelium of blood and lymphatic vessels; Bowman's capsule and thin loop of Henle in kidney; mesothelium lining pericardial, peritoneal and pleural body cavities; lung alveoli; smallest excretory ducts of glands

its functions are to lubricate body cavities (permits free movement of organs); pinocytotic transport across cells

Front 140

Stratified squamous keratinized epithelial

Back 140

Located on the epidermis of skin

It prevents loss of water; and protection

Front 141

Stratified squamous nonkeratinized epithelium (moist)

Back 141

Location - Mucosa of oral cavity, esophagus, anal canal; vagina; cornea of eye and part of conjunctiva

Functions - secretion; protection; prevents loss of water

Front 142

Simple cuboidal epithelium

Back 142

Location - kidney tubules; choroid plexus; thyroid gland; rete testis; surface of ovary

Function - Secretion; absorption; lines surface

Front 143

Stratified cuboidal epithelium

Back 143

Location - ducts of sweat glands; developing follicles of ovary

Function - Secretion and protection

Front 144

Simple columnar epithelium

Back 144

Cells lining lumen of digestive tract (stomach to rectum); gall bladder; many glands (secretory units and ducts); uterus; uterine tube (ciliated)

Functions - secretions; absorption; protection; lubrication

Front 145

Pseudostratified columnar epithelium

Back 145

Location - Lines lumen of respiratory tract (nasal cavity, trachea, and bronchi) (ciliated); ducts of epididymis (stereocilia); ductus deferens; male urethra

Functions - Secretion; protection; facilitates transport of substances on surface of cells

Front 146

Stratified columnar epithelium

Back 146

Location - male urethra; conjunctiva

Function - Protection

Front 147

Transitional epithelium

Back 147

Location - Urinary tract (renal calyces and pelvis, ureter and urinary bladder)

Function - Protection

Front 148

Name and define some specializations in epithelium tissue

Back 148

1. Microvilli - fingerlike projections from the cell surface, covered by plasma membranes and containing a core of microfilaments. Mainly located at luminal surfaces of absorptive cells

2. Cilia - motile organelles extending into the lumen, consisting of a covering of plasma membrane and a core of specifically arranged microtubules. Mainly located in respiratory epithelium and part of female reproductive tract.

3. Flagella - similar to cilia. primary examples are on spermatozoa

4. Stereocilia - are actually very elongated microvilli

Front 149

Define Connective Tissue and name the components

Back 149

-is the packing and supporting material of the body tissues and organs. It develops from mesoderm (mesenchyme).
1. Ground substance
2. Fibers
3. Cells

Front 150

Ground Substance (connective tissue)

Back 150

is located between the cells and fibers, both of which are embedded in it. It forms an amorphous intercellular material. In the fresh state, it appears as a transparent and homogenous gel. It acts as a route for the passage of nutrients and wastes to and form the cells within or adjacent to the connective tissue. The ground substance is composed of mucopolysaccharides, proteins, lipids and water. The primary glycosaminoglycans found in the ground substance are chondroitin sulfate and hyaluronic acid, the latter present in greater quantity.

Front 151

Fibers (connective tissue)
name the three kinds

Back 151

The fiber components of connective tissue add support and strength.
1. collagenous
2. elastic
3. reticular

Front 152

Collagen fibers

Back 152

(white fibers) are the most numerous fiber type and are present in all types of connective tissue in varying amounts. Collagen bundles are strong and resist stretching. They are found in structures such as tendons, ligaments, aponeuroses, and fascia, which are subjected to pull or stretching activities.

Front 153

Elastic fibers

Back 153

(yellow fibers) are refractile fibers, which are thinner then collagen fibers. They are extremely elastic and are located in structure with a degree of elasticity, such as the walls of blood vessels (elastic arteries), true vocal cords, and trachea.

Front 154

Reticular fibers

Back 154

are thinner than collagenous fibers. They are arranged in an intermeshing network, which supports the organ. Reticular fibers are inelastic. they are found in the walls of blood vessels, lymphoid tissues (spleen and lymph nodes), red bone marrow, basal laminae, and glands (liver and kidney)

Front 155

Cells (connective tissue)
Name the type of cells found in connective tissue

Back 155

the cells of connective tissue are primarily attached and nonmotile (fixed cells), but some have the ability to move (wandering or free cells).
1. Fibroblasts
2. Mesenchymal
3. Macrophages
4. Adipocytes
5. Mast cells
6. Plasma cells
7. Reticular cells
8. White blood cells

Front 156

Fibroblasts

Back 156

Constitute the largest number of cells present in connective tissue. In an actively secreting state, they are flattened stellate-shaped cells with an oval nucleus and basophilic cytoplasm due to the numerous rER. in the inactive state, they appear as elongated spindles with a more basophilic oval or elongated nucleous. In this state they are referred to as fibrocytes.

Front 157

Mesenchymal cells

Back 157

are undifferentiated connective tissue cells that have the potential to differentiate into other types of connective tissue cells. they are primarily found in embryonic and fetal tissues; some are thought to be present in the adult abutting the walls of capillaries. they are smaller the fibroblasts and are stellate in shape. They are capable of moving by extending their cell processes into the gel-like ground substance

Front 158

Macrophages

Back 158

(histiocytes) may be fixed or free. Free macrophages may wander through the connective tissue by extending their cell processes. Fixed macrophages are very numerous in loose connective tissue. They are polymorphic in shape and contain an oval nucleous. They have the ability to engulf extracellular material (foreign matter or necrotic cells). Macrophages are difficult to distinguish except when they are actively phagocytosing material and thus contain many vacuoles.

Front 159

Adipocytes

Back 159

(fat cells) are found in most connective tissue, either singly or in groups. If the connective tissue layer is primarily composed of face cells, it is referred to as adipose tissue. And adipocyte is a round, large cell with a distinct, dense nucleus usually located at the periphery of the cytoplasm. The majority of the cytoplasmic (cell) volume is taken up my a large lipid droplet. Due to the clear appearing cytoplasm and dark nucleus at one pole, the cell has a signet ring appearance. Fat cells do not undergo mitosis.

Front 160

Mast Cells

Back 160

are oviod cells with small round nuclei. The cytoplasm contains numerous coarse basophilic granules which also stain metachromatically and are soluble in water. the mast cell granules are composed of histamine and an anticoagulant known as heparin. Histamine dilates blood vessels and increase the permeability of capillaries, thus increasing interstitial fluid. Mast cells take part in the allergic response of the body. Mast cells are found in most connective tissue and are numerous in the respiratory tract and near small blood vessels

Front 161

Plasma Cells

Back 161

have a characteristic eccentric nucleus that contains chromatin arranged in a definite pattern near the nuclear envelope. This pattern gives a "cartwheel or spoke wheel" appearance. The juxtanuclear cytoplasm appears clear and less basophilic due to the Golgi complex located in this area. Plasma cells are found in the lamina propira of the gastrointestinal tract. they function in protecting the body against bacterial invasion by secreting antibodies (immunoglobulins (IgG)) into the circulating blood

Front 162

Reticular cells

Back 162

are star-shaped cells that join via their processes to form a cellular network. they are found abutting reticular fibers in certain glands and lymphoid tissues.

Front 163

White blood cells

Back 163

leukocytes - migrate out of the blood into the extracellular ground substance. The main leukocytes found in the connective tissue are lymphocytes, monocytes, eosinophils, basophils, and neutrophils. The leukocytes in connective tissue are similar in structure and function to those in the blood. The agranular leukocytes migrate in large numbers under normal conditions. lymphocytes accumulate in areas in response to chronic inflammation. Neutrophils also migrate in large number into the interstitium during an inflammatory response. Eosinophils occur in areas involved in allergic reactions, such as the respiratory tract.

Front 164

List terms of planes

Back 164

1. Midsagittal or median
2. Sagittal
3. Frontal or coronal
4. Transverse, horizontal or cross

Front 165

Define Midsagittal or median

Back 165

A vertical plane in the antero-posterior direction that divides the body into equal right and left halves

Front 166

Define Sagittal

Back 166

A vertical plane parallel to the midsagittal plane; it allows longitudinal slices that are parallel to the median plane

Front 167

Define Frontal or coronal

Back 167

A vertical plane that passes from side to side; it is at right angles to the midsagittal plane and cuts the specimen into anterior and posterior components

Front 168

Define transverse, horizontal or cross

Back 168

a horizontal plane at right angle both the sagittal and frontal plane; it cuts the specimen into superior (upper or cephalad) and inferior (lower or caudad) portions. Cross sections of the specimen are obtained

Front 169

Name all the terms of positions

Back 169

1. anterior or ventral
2. posterior or dorsal
3. superior, craniad, or cephalad
4. inferior or caudad
5. superficial or external
6. deep or internal
7. medial
8. lateral
9. proximal
10. distal
11. central
12. peripheral
13. plantar

Front 170

Anterior or ventral

Back 170

Toward the front of the body or belly side; (volar or palmar side are used in referring to the hand)

Front 171

Posterior or dorsal

Back 171

toward the back (the dorsum) of the body

Front 172

Superior, craniad, or cephalad

Back 172

in the direction of the head,; nearer the head

Front 173

Inferior or caudad

Back 173

in the direction of the feet; away from the hear

Front 174

Superficial or external

Back 174

Nearer the surface; without or nearer the outside of the body

Front 175

Deep or internal

Back 175

Away from the surface; within or toward the inside or interior

Front 176

Medial

Back 176

Nearer the midline of the body; toward the midsagittal plane or cent

Front 177

Lateral

Back 177

Farther from the midline; toward the side of the body or away from the midsagittal plane to the side

Front 178

Proximal

Back 178

Nearest a point of origin in general or nearest the trunk as far as the extremities are concerned; nearer the attachment to the body. Dearer the midline axis

Front 179

Distal

Back 179

Farther from the point of origin of a structure or farther from the reference point or the midline axis

Front 180

Central

Back 180

toward the center of the body; toward the inside

Front 181

Peripheral

Back 181

Away from the center of the body ; toward the outside

Front 182

Plantar

Back 182

sole of the foot

Front 183

List everything the human skeletal system provides

Back 183

(Endoskeleton)
1. support
2. protection of vital organs
3. sites for muscle attachment
4. storage sites of body calcium and phosphates
5. sites for blood cell formation

Front 184

The Human skeleton is divided into two things?

Back 184

Axial skeleton and appendicular skeleton

Front 185

Axial Skeleton

Back 185

consists of 80 bones forming the trunk (spine and thorax) and skull
Vertebral column, ribs and sternum, skull , middle ear bones, and the small U-shaped hyoid bone in the neck

Front 186

Appendicular Skeleton

Back 186

forms the major internal support of the appendages the upper and lower extremities (limbs)

shoulder girdle - clavicle and scapula
arm - humerus
forearm - radius (lateral) and ulna (medial)
Wrist - eight carpal bones
Palm - five metacarpal bones
Digits - phalanges
Pelvic Gridle - pubic, illeum, and ischium
Thigh - femur
Leg - tibia (medial) and fibula (lateral)
Foot - seven tarsal bones

Front 187

Bone
Name the two types of bones

Back 187

a specialized type of connective tissue consisting of cells (osteocytes) embedded in a calcified matrix that gives bone its characteristic hard and rigid nature. Bones are encased by periosteum, a connective tissue sheath. All bone has a central marrow cavity.

1. compact bone
2. spongy (cancellous) bone

Front 188

Compact bone

Back 188

lies within the periostum, forms the outer region of bones and appears dense due to its compact organization.

Front 189

Spongy bone

Back 189

consists of bars, spicules, or trabeculae, which form a lattice meshwork. Spongy bone is found at the ends of long bones and the inner layer of flat, irregular, and short bones.

Front 190

Name the three types of bone cells

Back 190

1. osteocytes
2. osteoblasts
3. osteoclasts

Front 191

Osteocytes

Back 191

are found singly in lacunae (spaces) within the calcified matrix and communicate with eat other via small canals in the bone known as canaliculi. they are similar in compact and spongy bone in structure and function

Front 192

Osteoblasts

Back 192

are cells that form bone matrix, surrounding themselves with it and thus are transformed into osteocytes. They arise from undifferentiated cells, such as mesenchymal cells.

Front 193

Osteoclasts

Back 193

are found during bone development and remodeling. They are multinucleated cell lying in cavities. Howship's lacunae, on the surface of the bone tissue being resorbed. Osteoclasts remove the existing calcified matrix releasing the inorganic or organic components

Front 194

Three definite units of muscles

Back 194

1. endomysium - extracellular matrix and very sparse, loose connective tissue layers enveloping a single fiber
2. perimysium - connective tissue layer enveloping a bundle of fibers
3. epimysium - connective tissue layer enveloping the entire muscle.

Front 195

Define flexion and the different types

Back 195

is bending most often ventrally to decrease the angle between two parts of the body
1. Extension - straightening, increasing the angle between two body parts
2. Abduction - movement away from the midsagittal plane (move laterally)
3. Addubtion - movement toward the midsagittal plane (back to mid-axis)
4. Circumduction - circular movement at a ball and socket
5. Rotation - movement of a part of the body around its long axis

Front 196

Supination

Back 196

refers only to the movement of the radius around the ulna. The body on its back is in the supine position

Front 197

Pronation

Back 197

refers to the palm of the hand being oriented posteriorly. the body on its belly is in the prone position

Front 198

Inversion and Eversion

Back 198

refers only to the lower extremity, specifically the ankle joint. When the foot is turned inward, so that the sole is pointing and directed toward the midline of the body and is parallel with the median plane.
Eversion is the opposite - refers to the foot being turned outward so that the sole is pointing laterally

Front 199

Events leading to muscle contraction

Back 199

1. Action potential of the axon the motoneuron
2. Depolarization of axon terminal
3. Ca+2 enters axon terminal
4. Acetylcholine (ACh) released into synaptic cleft
5. ACh diffuses across synapse
6. ACh binds to receptors on muscle end plate; degradation of ACh by acetylcholinesterase
7. Depolarization of muscle end plate (end plate potential)
8. Action potential in muscle
9. Action potential invades transverse (T) tubule
10. Ca2+ released from sarcoplasmic reticulum (SR)
11. Increased intracellular (Ca2+)
12. Ca2+ binds to troponin C on the thin filaments
13. Action and myosin bind, forming cross bridges
14. Cross bridges pivot
15. Thick and thin filaments slide, producing muscle tension
16. Ca2+ reuptake into sarcoplasmic reticulum by (Ca2+ ATPase)
17. Decreased intracellular (Ca2+)
18. Relaxation

Front 200

Where is the energy source for muscles?

Back 200

ATP which is ultimately from carbohydrates and lipids

Front 201

Name the three types of Muscle fibers and explain them

Back 201

1. White (fast) fibers - contract rapidly; fatigue quickly; energy production is mainly via anaerobic glycolysis; contain relatively few mitochondria; examples are muscles in the eye
2. Red (slow) fibers - contract slowly; fatigue slowly; energy production mainly via oxidative phosphorylation (aerobic); contain relatively many mitochondria; examples are postural muscles
3. Intermediate fibers - have structural and functional qualities between those of white and of red fibers

Front 202

The circulatory system serves to

Back 202

1. transport nutrients and oxygen to the tissues
2. remove waste materials by transporting nitrogenous compounds to the kidneys and carbon dioxide to the lungs
3. transport chemical messengers (hormones) to target organs and modulate and integrate the internal milieu of the body
4. transport agents which serve the body in allergic, immune, and infectious responses
5. initiate clotting and thereby prevent blood loss
6. maintain body temperature
7. produce, carry, and contain blood
8. transfer body reserves, specifically mineral salts, to areas of need

Front 203

The heart is composed of:

Back 203

endocardium (lining coat; epithelium)
myocardium (middle coat; cardiac muscle)
epicardium (external coat or visceral layer of pericardium; epithelium and mostly connective tissue)
impulse conducting system

Front 204

Cardiac Nerves

Back 204

Modification of the intrinsic rhythmicity of the heart muscle is produced by cardiac nerves of the sympathetic and parasympathetic nervous system. Stimulation of the sympathetic system increase the rate and force of the heartbeat and dilates the coronary arteries. Stimulation of the parasympathetic (vagus nerve) reduces the rate and force of the heartbeat and constricts the coronary circulation. Visceral afferent (sensory) fibers from the heart end almost wholly in the first four segments of the thoracic spinal cord

Front 205

Cardiac Cycle

Back 205

Alternating contraction and relaxation is repeated about 75 times per minute; the duration of one cycle is about 0.8 sec. Three phases succeed one another during the cycle
1. atrial systole; 0.1 sec
2. ventricular systole; 0.3 sec
3. diastole: 0.4 sec

Front 206

The circulatory system is organized as two anatomically and functionally distinct subdivision:

Back 206

1. Blood Vascular Subdivision
2. Lymph Vascular Subdivision

Front 207

Blood Vascular Subdivision

Back 207

Functionally, this subdivision of the circulatory system consists of two different circulatory routes; the systemic route and the pulmonary route. Systemic arteries originating from the left side of the heart (via the aorta) distribute oxygen-poor and nutrient-rich blood to all parts of the body. Systemic veins return oxygen-poor and nutrient-poor blood back to the right side of the heart (via vena cavae). Pulmonary arteries deliver this blood from the right side of the hear to the lungs, and pulmonary veins return oxygen-rich blood back to the left side of the heart.

Front 208

Name the pathway of blood flow through the heart

Back 208

venous blood returns to heart via inferior/superior vena cavae ->right atrium -> tricuspid valve -> right ventricle -> pulmonary semilunar valve -> pulmonary arteries -> lungs (i.e. smaller arteries, capillary beds, smaller veins) -> pulmonary veins -> left atrium -> bicuspid valve -> left ventricle -> aortic semilunar valve -> aorta

Front 209

Lymphatic Drainage:

Back 209

A network of lymphatic capillaries permeates the body tissues. Lymph is a fluid similar in composition to blood plasma, and tissue fluids not reabsorbed into blood capillaries are transported via the lymphatic system eventually to join the venous system at the junction of the left internal jugular and subclavian veins. Like veins, lymphatics posses valves. Interposed along the course of some lymph vessels are lymph nodes. These nodes filter lymph and add lymphocytes to the circulation. Lymph nodes possess an outer cortex and an inner medulla. Lymphoid follicles are present in the cortex; irregular cords of lymphocytes make up the medulla

Front 210

Plasma in blood

Back 210

Over 90% of plasma is water; the balance is made up of plasma proteins and dissolved electrolytes, hormones, antibodies, nutrients, and waste products. Plasma is isotonic. Plasma plays a vital role in respiration, circulation, coagulation, temperature, regulation, buffer activities, and overall fluid balance. The plasma proteins (albumin, globulin, and fibrinogen) are responsible for the viscosity of blood, for carrying immune material and for controlling osmotic pressure. Fibrinogen in bleeding is transformed into fibrin and helps form a clot.

Front 211

Name the two types of blood cells.

Back 211

1. Erythrocytes (Red Blood Cells RBC)
2. Leukocytes (White Blood Cells WBC)

Front 212

Erythrocytes

Back 212

Red Blood Cells (RBC) - these cells are biconcave discs. Mature cells lack a nucleus. Hemoglobin, a complex molecule of iron and protein, is present in the cell. RBC carry oxygen (in the form of oxyhemoglobin) from the lungs to the tissues and transport carbon dioxide from the tissues to the lungs. The membranes of the RBC carry Rh antigen and blood group antigens. RBC have a life span of about 3 months. They are removed from the circulation by the spleen and replaced by new RBC formed in bone marrow.
In the breakdown of hemoglobin, bilurubin is excreted and iron is retained`

Front 213

Leukocytes
Name the two types

Back 213

White Blood Cells (WBC) They differ from RBC by having a nuclei and exhibiting ameboid movement. WBC contain phosphatases, liberate proteolytic enzyme, and function mainly in phagocytosis, proteolysis, and antibody formation.
An increase in the number of leukocytes is called leukocytosis, and decrease is called leukopenia
1. Granular
2. Agranular

Front 214

Granular leukocytes
Name all the types

Back 214

They possess abundant cytoplasmic granules
1. Neutrophils
2. Eosinophils
3. Basophils

Front 215

Neutrophils

Back 215

Granular Leukocytes
Make up 65 to 75% of total leukocytes. They are twice as large as erythrocytes. They are phagocytic and active in innate defense mechanism. Dead neutrophils become pus.

Front 216

Eosinophils

Back 216

Granular Leukocytes
Make up 2 to 5% of total leukocytes They possess large, red, acidophilic granules and a bilobed nucleus. Large number are found at sites of parasitic infections and allergic reactions (specially, in the respiratory or digestive tracts) They function in the destruction of antigen-antibody complexes and defend against large parasites.

Front 217

Basophils

Back 217

Granular Leukocytes
make up 0.5% or less of total leukocytes. They possess large purple, basophilic granules that contain heparin (an anticoagulant), histamine (a vasoactive substance), and other components

Front 218

Agranular leukocytes
Name the types

Back 218

do not possess abundant cytoplasmic granules
1. lymphocytes
2. monocytes

Front 219

Lymphocytes

Back 219

Agranular leukocytes
make up 20 to 25% of total leukocytes. They originate from lymphoid tissue and bone marrow, are prevalent at sites of chronic inflammation, and function in specific immune responses

Front 220

Monocytes

Back 220

Agranular leukocytes
make up 3 to 8% of total leukocytes. After extravasation and migration into connective tissues, monocytes differentiate into macrophages, which function in both innate defense mechanism and specific immune responses

Front 221

Blood platelets

Back 221

these cytoplasmic structures are not true cells but are cell fragments characteristic of mammalian blood. These structures arise by the fragmentation of cytoplasmic processes of giant bone marrow cells. Platelets agglutinate and adhere to regions of injured vessels; they plug wounds of blood vessels. They help physically in clotting and form thromboplastin, an integral chemical component of clot formation

Front 222

Blood Clotting and the steps

Back 222

Platelets contribute thromboplastin (thrombokinase), an enzymatically active substance.
Platelets -> Thromboplastin
then
Prothrombin + Ca2+ -> thrombin
then
Fribrinogen -> fibrin

Front 223

Anticoagulants
Name examples

Back 223

is a substance that prevents or retards coagulation of blood.
Examples
1. herparin - an acid mucopolysaccharide which occurs most abundantly in the liver
2. aspirin (acetylsadicylic acid) which also acts as an analgesic, antipyretic, antirheumatic compound
3. Dicumarol (bihydroxycoumarin) drug

Front 224

Blood Pressure

Back 224

is usually measured by placing a sphygmomanometer cuff around the arm compressing the brachial artery and vein. Maximum blood pressure is obtained during ventricular contraction (systole) and minimum blood pressure indicates ventricular rest (diastole).

Front 225

Heartbeat is initiated by the

Back 225

S-A (sino-atrial) node

Front 226

Components of the respiratory system

Back 226

1. Nasal passageways - external/anterior nares, nasal cavities, internal/posterior nares
2. pharynx - nasopharynx and oropharynx
3. larynx - contains false and true vocal cords
4. trachea
5. left and right extrapulmonary bronchi
6. left and right lungs - contains intrapulmonary bronchi, bronchioles (terminal and respiratory), and alveoli organized as alveolar ducts and alveolar sacs

Front 227

Pathway of gas exchange in the alveoli

Back 227

air in alveoli - surfactant (lowers surface tension) - alveolar epithelium (simple squamous) - fused basal laminae of alveolar epithelium and capillary endothelium - capillary endothelium (simple squamous) - blood plasma - erythrocytes/ rbc

Front 228

Four factors that affect the affinity of hemoglobin for oxygen:

Back 228

1. decrease in pH
2. increase in temp
3. increase in concentration of 2,3 diphosphoglycerate (DPG)
4. carbon dioxide

Front 229

Structures that make up Nephron

Back 229

Renal corpuscle
proximal convoluted tubule
descending loop of Henle
Ascending loop of Henle
Distal convoluted tubule
collecting ducts

Front 230

Define the function and nature of the urine for a Renal corpuscle

Back 230

function - delivers blood,make ultrafiltration

Urine - same as plasma, contains equivalent electrolytes, is isosmolar, very little albumin

Front 231

Define the function and nature of the urine for a Proximal convoluted tubule

Back 231

Function - active transport reabsorption of sugars, amino acids, bicarbonate, and electrolytes, passive water reabsorption, secretion of uric acid and other waste

urine - diminished volume, isosmolar with respect to plasma

Front 232

Define the function and nature of the urine for a descending loop of Henle

Back 232

Function - passive diffusion of water, Na and Cl out into medulla; water remains in medulla, while Na and Cl diffuse back into loop

urine - smaller volume, hypertonic with respect to plasma

Front 233

Define the function and nature of the urine for a ascending loop of Henle

Back 233

functions - impermeable to water, cl actively pumped to interstitium; Na follows passively

urine - little change in volume; becomes hypotonic

Front 234

Define the function and nature of the urine for a Distal convoluted tubule

Back 234

Function - Reabsorption of Na, secretion of K and H; regulated by aldosterone; excretion of fixed acids, net H excretion

urine - Decreased pH, lower Na, and very little bicarbonate, volume can change

Front 235

Define the function and nature of the urine for a Collecting Ducts

Back 235

functions - variably permeable to water; regulated by antidiuretic hormone (ADH)

urine - both volume and osmolarity vary, depending upon ADH secretion by neurohypophysis

Front 236

Ureter

Back 236

is a long muscular tube that connects the renal pelvis to the urinary bladder.

Front 237

Name the physiological processes occuring during the production of urine

Back 237

1. Filtration
2. Reabsorption
3. Secretion
4. Passive diffusion

Front 238

Filtration in urine

Back 238

the production of an ultra filtrate of plasma within Bowman's space

Front 239

Reabsorption in urine

Back 239

The selective removal of material from the ultrafiltrate as it passes through the tubular nephron and the return of these substances into peritubular capillaries.
Reabsorption of filtered amino acids, filtered glucose, sodium, chloride, bicarbonate, calcium, magnesium, and phosphate

Front 240

Secretion in urine

Back 240

the cells forming the nephron actively secrete material into the filtrate

Front 241

Passive diffusion in urine

Back 241

diffusion of fluid along the osmotic gradient

Front 242

Name the three parts of skin

Back 242

1. Epidermis
2. Dermis
3. Hypodermis (subcutaneous tissue)

Front 243

Name and briefly describe the layers of the epidermis

Back 243

1. stratum basale (germinativum) - simple cuboidal to columnar epithelial calls this is the basal lamina. This is where Melanocytes are located (melanin) pigmentation
2. Stratum spinosum - consists of several layers of polygonal cells which adhere to each other via desmosomes
3. Stratum granulosum - has membrane coating granules. this intercellular material appears to block the passage of substances through the epidermis.
4. Stratum lucidum - flattened cells whose organelles and nuclei are indistinct or absent
5. Stratum corneum - Composed of layers of compressed, flat, cornified (keratinized) cells which lack nuclei and organelles.

Front 244

Dermis
name the two strata

Back 244

also known as corium this is derived from the mesoderm and is connective tissues layer between the epidermis and hypodermis.
1. papillary layer
2. reticular layer

Front 245

Name the two kinds of glands

Back 245

1. Sebacceous Glands - release oily secretions not on the palms or soles
1. Sweat Glands - watery fluid containning ammonia, urea, uric acid, and sodium chloride.

Front 246

Sweat Glands
list the importance and the types

Back 246

important for the excretion of some body wastes and the regulation of body temp and is under nervous system control

two types
1. Eccrine Sweat Glands
2. Apocrine Sweat Glands

Front 247

Define calorie

Back 247

each one of which is 1/1000 of a kcal (kilocalorie), or the energy necessary to raise 1g of water one degree Celsius.

Front 248

Name all the Fat-Soluble Vitamins

Back 248

Vitamin A (Retinol)
Vitamin D (Calciferol)
Vitamin E (Tocopherol)
Vitamin K

Front 249

Vitamin A physiological role and deficiency

Back 249

Also known as retinol, retinoic acid, retinal
Contributes to visual pigments in eye

deficiency - night blindness, drying of mucous membrances in body

Front 250

Vitamin D physiological role and deficiency

Back 250

Also known as calciferol.
Absorption of calcium and phosphorus; construction of teeth and bones

deficiency - Rickets (especially in children)

Front 251

Vitamin E physiological role and deficiency

Back 251

Also known as Tocopherol
Protects blood cells from destruction during formation

deficiency - lysis of red blood cells, anemia

Front 252

Vitamin K

Back 252

Fat soluble
Used in synthesis of prothrombin required for blood clotting

deficiency - Excessive bleeding (especially in newborns); poor blood clotting

Front 253

Water-Soluble Vitamins

Back 253

1. Thiamine (B1)
2. Riboflavin (B2)
3. Pyridoxine (B6)
4. Cyanocobalamin (B12)
5. Niacin (B3)
6. Ascorbic acid (C)
7. Pantothenic acid
8. Biotin
9. Folic acid

Front 254

Thiamine physiological role and deficiency

Back 254

Vitamin B1 water-soluble
Coenzyme in carbohydrate metabolism

deficiency - beriberi, loss of appetite, fatigue

Front 255

Riboflavin physiological role and deficiency

Back 255

Vitamin B2 Water-Soluble
Part of FAD, coenzyme in respiration and protein metabolism

deficiency - Inflammation and break down of skin

Front 256

Pyridoxine physiological role and deficiency

Back 256

Vitamin B6 Water-soluble
Coenzyme in amino acids and fat metabolism

deficiency - Anemia, nerve problems

Front 257

Cyanocobalamin physiological role and deficiency

Back 257

Vitamin B12 Water-soluble
Coenzyme in formation of erythrocytes (rbc) and nucleic acids

deficiency - Pernicious anemia

Front 258

Niacin physiological role and deficiency

Back 258

Vitamin B3 Water-Soluble
Part of NAD, coenzyme in energy metabolism

deficiency - Pellagra, fatigue

Front 259

Ascorbic Acid physiological role and deficiency

Back 259

Vitamin C Water-soluble
Assists synthesis of collagen in connective tissues

deficiency - scurvy, anemia, slow wound healing

Front 260

Pantothenic Acid physiological role and deficiency

Back 260

Water-soluble
Part of coenzyme A, used in carbohydrate and fat mebaolism

Front 261

Biotin physiological role and deficiency

Back 261

Water-soluble
Coenzyme in addition of carboxyl groups

deficiency is rare since trace amounts are needed

Front 262

Folic acid physiological role and deficiency

Back 262

Water-soluble
Coenzyme in formation of nucleotides and hemoglobin

deficiency - some types of anemia

Front 263

The Oral Cavity

Back 263

Contains the tongue and teeth and receives the secretions from the salivary glands
The tongue is composed primarily of a core of skeletal muscle and glands and covered by a mucous membrane.

Front 264

Name and briefly describe the general structural plan of the tubular digestive tract

Back 264

1. Mucosa - contain moist surface (epithelium) then connective tissue, and a thin muscular layer
2. Submuscosa - connective tissue that are rich in blood vessels
3. Muscular tunic - inner circular smooth muscle layer and outer longitudinal smooth muscle layer
4. Adventitia or serosa - connective tissue containing blood vessels, nerves, and lymphatics

Front 265

Esophagus

Back 265

The upper third of the esophagus features skeletal muscle (voluntary), the middle third both skeletal and smooth (involuntary) muscle, the lower third only only smooth muscles

Front 266

The Stomach
Name and briefly describe the two types of gastric glands

Back 266

is highly vascular, contains gastric glands, and has smooth muscle fibers extending around the glands
two types
1. cardiac - and pyloric glands secrete mucus (protects against autodigestion and neutralizes acid to a small degree
2. fundic - parietal or oxyntic cells secrete HCl.

Front 267

Small Intestine name three major regions
Large Intestine name regions

Back 267

Small Intestines
1. Duodenum (10 in.)
2. Jejunum (8.5 ft)
3. Ileum (12.5 ft)

Large Intestines
1. Cecum (appendix is attached here)
2. Ascending colon
3. Transverse colon
4. Descending colon

Front 268

Pancreas

Back 268

has both an exocrine and endocrine secretory function. Two excretory ducts are usually present and enter the second part of the duodenum. Exocrine glandular elements are arranged in acini. Acinar cells have a basal zone containing extensive rER and an epical zone containing zymogen granules which are the precursors of the enzymes in pancreatic juice namely trypsin, chymotrypsin, amylase, carboxypeptidase, and lipase.
Trypsin, chymotryspin, and carboxypeptidase attack proteins and polypeptides and eventually render amino acids which can be absorbed
Pancreatic lipase, amylase, and proteases are controlled by the presence of foodstuffs and hormones.
Islets of Langerhans are the endocrine portion of the pancreas. The endocrine cell aggregations are interspersed irregularly among the acini. Three cell types of cells:
1. A, or alpha cells, which are presumed to form glucagon
2. B, or beta cells, which are more numerous then A cells and produce insulin
3. D, or delta cells which are the least numerous and produce somatostatin

Front 269

Liver

Back 269

anatomically interposed between the intestine and the heart
Major Function:
1. Synthesis and storage of glycogen
2. Maintenance of blood glucose homeostasis
3. Production of glucose from amino acids, lactic acid, or glycerol
4. Synthesis of nonessential amino acids and catabolism of all, except the branched chain
5. Detoxification of ammonia, released from amino acids through synthesis of urea
6. Fatty acids synthesis, storage, and metabolism of lipoproteins
7. Fatty acid catabolism by the beta-oxidation cycle and production of ketone bodies
8. Removal of bile pigment, derived from hemoblobin breakdown, from the blood and secretion into the bile
9. Synthesis of albumin, the cheif intravascular protein, and several proteins involved in coagulation
10. Storage of many lipid and water soluble vitamins
11. Detoxification of drugs and other harmful substance
12. Embryonic hematopoietic (red blood cell producing) organ

Front 270

Gallbladder

Back 270

bile, which is a composite of bile salts, bile acids, and bile pigments as well as electrolytes secreted continuously by the hepatocytes, is collected and stored in the gallbladder. The bile salts and acids, synthesized from cholesterol are critical for normal fat digestion in the intestine, since they enable micelle formation. Certain drugs and their hepatic salts, so that 95% of the amount excreted per day is returned to the liver via the cyclical path called the enterohepatic circulation. Since steroid hormone is made from the cholesterol nucleus, the 5% which is lost is a major excretory pathway for steroid hormone precursors

Front 271

Name and briefly describe the hormones of the digestive tract

Back 271

1. Gastrin - stimulates gastric acid and pepsinogen secretion
2. Secretin - stimulates pancreas to secrete pancreatic fluid and bicarbonate and biliary fluid secretion and bicarbonate
3. Cholecystokinin - stimulates pancreatic enzyme secretion

Front 272

Nervous system is divided into:

Back 272

1. Central nervous System (brain and spinal cord)
2. Peripheral nervous system (peripheral nerves and ganglia)
the peripheral is divided into:
1. somatic system
2. visceral (autonomic system)

Front 273

Cells of Nervous Tissue and what is in them

Back 273

Neurons
1. Dendrites
2. Cell body
3. axon hillock
4. Schwann cells
5. Nodes of Ranvier
6. myelin sheath
7. axon
8. synaptic terminals

Front 274

Dendrites

Back 274

pick up an impulse and carry it toward the cell body
they are direct extensions of the cytoplasm and are generally multiple
they provide an increased surface area, the dendritic zone, to allow for synaptic interaction

Front 275

Action potential requires which two ions?

Back 275

sodium and potassium