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126 Cards in this Set

  • Front
  • Back
cohesion
ability to sick together
capillary action
allowing water to creep up narrow tubing
carbon
4 electrons available to form bonds
organic chemistry
study of the variety and complexity of carbon molecules
functional groups
organic molecules that share similar properties because they have similar clusters of atoms
hydroxyl
- -OH
-alcohols
-polar
-hydrophilic
carboxyl
-C03
-carboxylic acids
-weak acids
amino
-NH2
-amines
-weak bases
phosphate
-PO4
-organic phosphates
-acids
methyl
-CH3
-hydrophobic
ketone
-CO2
-keytones
-polar
-hydrophilic
aldehyde
-CHO2
-polar
-hydrophilic
carbohydrates
3 groups according to number of sugar molecules present
monosaccharides
-simplest carb
ex. fructose/glucose
disaccharides
-consists of 2 linked sugar molecules
ex. glucose + fructose= sucrose
polysaccharides
consists of a series of connected monosaccharides
polymer
any molecule that consists of a repeating molecular unit
starch
-a polysaccharide made of 1000 or more a-glucose molecules
-used in plants for energy storage
lipids
-insoluble in water but soluble in nonpolar substances
saturated (fatty acid)
-has single covalent bond between each pair of carbon atoms and each carbon has 2 hydrogens bonded to it
unsaturated (fatty acid)
-a double covalent bond replaes a single covalent bond and 2 hydrogen atoms
phospholipids
-simplar to lipids except one of fatty acid chains is replaced by a phosphate group
steroids
-classified with lipids
-backbone of 4-linked carbon rings
protein
-polymers of amino acids (covalently bonded)
peptide bonds
bonds between amino acids
4 levels of the structure of a protein
1. primary- order of aminos 2. secondary- shape from hydrogen bonding between amino acids
-alpha-spiral
-beta pleated
3. tertiary- structure from interactions among R groups
4. quaternary- assemply from peptide chains
globular proteins
proteins whose shape is dominated by teriary structure interactions
metabolism
chemical reactions that occur in biological systems
catabolism
breakdown of substances
sybthesis
formation of new products
substrate
substance which the ensyme acts
denatured
lose their 3D shape as Hydrogen bonds and peptide bonds begin to break down
ATP
common source of activation energy for metabolic reactions
cofactors
nonprotein moleclues that assist enzymes
coenzymes
organic cofactors
allosteric effector
activates or inhibits the enzyme's ability to catalyze a reaction
feedback inhibition
acts as an allosteric effector and shuts down one of enzymes catalyzing the reactions series
competitive inhibition
a substance inhibits an enzyme by occupying the active site, thus displacing the substrate
plasma membrane/cell membrane
-bounds the cell
-separator of internal metabolic events from the external environment
-controls the movement of materials into and out of the cell
-consists of a double phospholipid membrane (lipid bilayer) with the nonpolar hydrophobic tails and polar hydrophilic heads
Proteins and cholesterol molecules are scattered throughout the _________.
flexible phospholipid membrane
phospholipid membrane
a hydrophobic barrier to the movement of most molecules. small mulecules, such as H2O, CO2, and O2, freely pass across the membrane
channel proteins
provide passageways throught eh memebrane for certain water-soluble substance
transport proteins
spend energy (ATP) to transfer materials across the membrane.
active transport
when ATP is used by transferring materials across the membrane
recognition proteins
Recognize other cells and aid in sticking to other cells
-these proteins have short polysaccharide (oligosaccharide) chains attached to their surfaces extending out tfrom the cell
receptor proteins
receptors for hormones and other trigger molecules that alicit specific cell responses
electron transfer proteins
involved in transferring electrons from one molecule to another during chemical reactions
Inside the cell membrane are ________ in a a fluid cytoplasm (or cytosol).
organelles
organelles
bodies that serve to physically separate the carious metabolic reactions that occur wiwthin cells.
nucleus
-bounded by the nuclear envelope<br />-contains chromosomes<br />-serves as the site for the separationi of chromosomes during cell division
nuclear envelope
-a phospholipid bilayer similar to the plasma membrane
chromosomes
made up of one long DNA molecule with various proteins (including histones)
Nucleosomes
Histone proteins served to organize the lengthy DNA, coiled into bundles
nucleolus
a portion of DNA that manufactures the components of ribosomes
ribosomes
shipped to the cytoplasm where they assemble amino acids into proteins
endoplasmis reticulum (ER)
-stacks of flattened sacs involved in the production of various materials
rough ER
-ribosomes are attached
-serves to attach polysaccharide groups to polypeptides as they are assmbled by the ribosomes
smooth ER
-without ribosomes
-responsible for the synthesis of lipids and hormones, especially in cells that produce these substances for export from the cell
-in liver cells, it is involved in the breakdown of toxins, drugs, and toxic by-products from cellular reactions
golgi body/complex/apparatus
-group of flattened sacs arranged like a stack of bowls
-modify and package proteins and lipids into vesicles, small round-shaped sacs that bud fro the ends of a Holgi body. Vesicles often migrate to and merge with the plasma membrance, releasing their contents to the outside of the cell
lysosome
-vesicles from Golgi bodies that contain digestive enzymes
-break down food, cellular debris, and foreign invaders such as bacteria
mitochondria
-carry out aerobic respiration from carbohydrates
aerobic respiration
a process of obtaining energy in the form of ATM from carbs
chloroplasts
-carries out photosynthesis
photosynthesis
the process of incorporating energy from sunlight into carbohydrates
microtubules
-made of the protein tubulin
-function to provide support and motility for cellular activites
-found in the spindle apparatus which guides the movement of chromosomes during cell division and in flagella and cilia, structures that project from the plasma membrane and provide motility to the cell
intermediate filaments
-provides support for maintaining the shape of the cell
microfilaments
-made of protein actin
-involved in cell motility
-found in muscle cells and in cells that move by changing shape, such as the amoeba
flagella and cilia
-structures that protrude from the cell memebrane and make wavelike movements
-classified by their lengths and by their numbers per cell: -flagella-long and few
-cilia-short and many
-structually both consist of mibrotubules arranged in a "9 + 2" array --> nine pairs of microtubules arranged in a circle surrounding a pair of microtubules
Centrioles and basal bodies
-acts as microtubule organizing centers, or MTOCs
-made up of nine triplets arranged in a circle
Centrioles
-outside the nuclear envelope gives rise to the microtubules that make up the spindle apparatus used during cell division
Basal bodies
at the base of each flagellum and cilium and appear to organize their development
Most plant cells lack _____.
centrioles.
Cell walls
-found in plants fungi, protists, and bacteria
-develops outside the plasma membrane
-provides support for the cell
-consists of cellulose
cellulose
a polysaccharide made from B-glucose
Cell walls of fungi are usually made of _____ or ______.
cellulose or chitin
chitlin
a modified polysaccharide differing from cellulose in that one of hydroxyl groups is replaced by a group containing nitrogen
-makes up exoskeleton of arthropods
vacuoles
-found in plants
-fluid filled bodies that occupy the major portion of the plant cells
-maintains cell ridigity by the turgor on the cell walls
turgor
pressure
peroxisomes
-single-membrane organelles that break down various substances
-common in livers of animals (where they break down toxic substances) or in plant cells where they break down toxic by-products of certain photosynthetic processes
Differences in plant and animal cells
1. Plant cells have cell walls. Animal cells don't.
2. Plant cells have chloroplasts. Animal cells don't.
3. Plant cells OFTEN have large central vacuoles. Animal cells don't.
4. Animal cells have centrioles. Plant cells USUALLY don't.
Eukaryotic organisms
all living thigns except for bacteria and cyanobacteria
Differences in eukarotes and prokaryotes
1. The hereditary material exists as a single "nakes" DNA molecule without the proteins that are associated with the DNA in eukaryotic chromosomes
2. Prokaryotic ribosomes are smaler than those of eukaryotes
3. The cell walls of bacteria, when present are constructed from peptidoglycans, a polysacharide- protein molecule
4. Flagella, when present, are not constructed of microtubules
Bulk flow
overall movement of a group of substances
ex. blood moving through a blood vessel
Concentraction gradient
Concentration of certain molecules/atoms/ions is different from one region to another, then the molecules which are constantly moving will eventually become evenly distibuted.
diffusion
-the net movement of substances from an area of higher concentration to an area of lower concentration
-occurs as a result of the RANDOM motion of the moecules
selectively permeable
allows only certain substances to pass
ex. plasma membrane
solvent
what something is dissolved in
solute
what is being dissolved
hypertonic
higher concentration of solute
hypotonic
lower concentration of sulutes
isotonic
equal concentration of solutes
Energy is required when substances are moved ____ a gradient.
against
osmosis
-diffusion of water molecules across a selectively permeable membrane
osmotic pressure
-hydrostatic pressure built up by the movement of water into a body by osmosis
-the turgor of plant cells results from osmotic pressure
dialysis
-diffusion of solutes across a selectively permeable membrane
The term _________ is usually used when different solutes are separated by the use of a selectively permeable membrane.
Dialysis
Plasmolysis
movement of water out of a cell (osmosis) that results in the collaspse of the cell (especially plant cells with central vacuoles)
passive transport/facilitated diffusion
movement of solutes through channel proteins in a plasma membrane.
*Water can pass through the pasma membrane without the aid of specialized proteins.
active transport
the movement of solutes against a gradient with the aid of a transport protein and the expenditure of energy (usually ATP)
exocytosis
the process of vesicles or other bodies fusing with the plasma membrand and releasing their contents to the outside of the cell.
*common when cell produces substances for export
endocytosis
capture of a substance outside the cell when the plasma membrane merges to engulf it
3 kinds of endocytosis
1.Phagocytosis: "cellular eating" occurs when UNDISSOLVED material enters the cell. The plasma membrand wraps around the solid material and engulfs it. Ex. how single celled protists capture food
2. Pinocytosis: "cellular drinking" occurs when DISSOLVED substances enter the cell. The plasma memebrane wraps around the material and forms a vesicle that contains the engulfed material
3.Receptor-mediated endocytosis: occurs when specific molecules int he fluid surround the ell bond to specialized recoptors int he plasma membrane. The folding of the plasma membrane and formation of a vesicle follows. *describes how cells receive specific hormones
countercurrent exchange
-movement of substances between two regions in which substances are moving bulk flow
-direction of bulk flow movement in the two regions are opposite.
ex. blood in the ills of fish move through vessels in the opposite direction of the surronding water that rans past them. As a result, the rate of diffusion of oxygen from water into the blood is grealy increased.
photosynthesis
the prcess of converitng energy fron sunlight to energy in chemical bonds
general formula of photosynthesis
light+ 6H2O+6CO2=C6H12O6 + 6O2
C6H12O6, CH02, (CH2O) is..
glucose or any carbohydrate
The process of photosynthesis
1. light-absorbing pigments in plant cells
2.energy from the light is incorportated to electrons within the atoms that make up the molecule
3. this energized/excited electroms are unstable and most immedgiately re-emit the absorbed energy
4. The energy is reabsorbed by electrons of a nearby bigment molecule.
5. The process of energy absorption, followed by re-emission of energy, continues, with the energy bouncing from one pigment molecule to another.
6. The process ends when the energy is absorved by one of two special chlorophyll a molecules, P680 and P 700.
P680 and P 700
-represents the wavelength at which they absorb their maximum amounts of light
-are different from other chlorophyll molecules because of their association with carious nearby pigments
-P700 forms a pigment cluster called photosystem I (PS I)
-P680 forms photosynthesis II (PSII)
photophosphorylation
process of mamking ATP from ADP and Pi (phosphorylation) using energy derived from light (photo).
Calvin-Benson Cycle
"fixes" CO2
-takes chemically unreactive, inorganic CO2 and incorporates it into an organic molecule that can be used in biological systems
-in order to produce a single molecule of glucose (C6H12O6) it must repeat six times and use 6 CO2 molecules.
-Known as C3 photosynthesis because the first product formed, PGA (phosphoglycerate), contains three carbon atoms.
-aka Calvin cycle and carbon reductin cycle
*no light is directly used
--> thus these reactioins are often called light-independent reactions or dark reactions
-Basically takes CO2 from the atmosphere and the energy in ATP and NADPH to create a glucose molecule. The energy in ATP and NADPH represents energy from the sun captured during photophosphorylation.

6 CO2+ 18 ATP + 12 NADPH + H+ = 18 ADP + 18 Pi + 12 NADP+ + 1 glucose
Carboxylation
-6 CO2 combine with 6 RuBP to produce 12 PGA
-RUBP carboxylase, or rubisco, catalyzes the merging of CO2 and RUBP
Reduction
-12 ATP and 12 NADPH are used to convert 12 PGA to 12 PGAL
-The energy in the ATP and NADPH molecules is incorporated into PGAL (Phosphoglyceraldehyde), thus making PGAL a very energy-rich molecule
regeneration
-6 ATP are used to convert 10 PGAL to 6 RuBP
-Regenerating the 6 RUBP orginally used to combine with 6 CO2 allows the cycle to repeat
carbohydrate synthesis
-The remaining PGAL are used to build glucose, a common energy-storing molecule
-Glucose molecules can be combined to form disaccharides like sucrose and polysaccharides like ctarch and cellulose
chloroplasts
sites wehre both the light-dependent and light independent reactions of photosynthesis occor
-consists of an outside phospholipid bilayer membrane enclosing a fluid called stroma
-light reactions occur on the thylakoid membranes, and the dark reactions occur in the stroma
thylakoids
suspended within the stroma are stacks of pancakelike membranes
-light- absorbing pigments and enzymes for the light-dependent reactions
granum (pl. grana)
entire stack of thylakoids
Chemiosmotic theory
-describes the mechanism by which ADP is phosphorylated to ATP
1. H+ ions (protons) accumulate inside thylakoids
2. A pH and electrical gradient across the thyladoid membrane is created- As H+ accumulate inside the thylakoid, the pH decreasesRhe H+ concentration decreases in the stroma and its pH increases. This creates a pH gradient consisting of differences in the concentration of H+ across the thylakoid membrane from a stroma pH 8 to a thylakoid pH 5 (a factor of 1000). Since H+ is positive, their accumulation on the inside of the thylakoin creates an electric gradient too.
3. ATP synthases generate ATP
-The pH and electrical gradient repesent potential energy like water dehind a dam.
channel proteins/ATP synthases
allow the H+ to flow through the thylakoid membrane and out to the stroma. The energy generated by the passge of H+ provides the energy for the ATP synthases to phosphorylate ADP to ATP. The passage of about 3 H+ is required to generate one ATP.
__________ is the most common protein on earth.
Rubisco
Photorespiration
biosynthetic pathway that leads to the fixation of oxygen
Peroxisomes
-found near chloroplasts where they function to break down photorespiration products
The purpsoe for moving ____ to bundle sheath cells is to increase the efficiency of photosynthesis.
CO2
C4 Photosynthesis
-Instead of being fixed by rubisco into PGA, the CO2 combines with PEP(phosphoenolpyruvate) to form OAA. The fixing enzyme is PEP carboxylase. OAA, the first product of this pathway has 4 carbon atoms, thus thet name C4. OAA is converted to malate, and the malate is shuttled to specialized cells within the leaf, the bundle sheath cells. THere, malate is converted to pyruvate and CO2.
Crassulacean acid metabolism (CAM)
the shysicology of this pathway is almost identical of C4 photosynthesis, with some changes.
-1. PEP carboxylas fixes CO2 to OAA, as in C4. Instead of malate, however, OAA is converted to malix acid.
-2. Malic acid is shuttled to the vacuole of the cell, not moved out of the cell to bundle sheath cells as in regular C4.
-3. Stomata are open at night. During the night, PEP carboxylase is active and malic acid accumulates in the cell's vacuole.
-4. Stomata are closed during the day (the reverse of other plants) Then the malic acid is shuttled out of the cabuole and converted back to OAA (requires 1 ATP to ADP), releasing CO2. The Co2 is now fixed by rubisco, and the Calvin-Benson cycle proceeds
advantage of CAM
photosynthesis can proceed during the day while the stomata are closed, greatly reducing H2O loss. As a resule, CAM provides an adaptation for plants that grow in hot, dry environments with cool nights.