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68 Cards in this Set
- Front
- Back
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Cells
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are extremely diverse and require a microscope to be seen
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Surface-area-to-volume-ratio
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is why cells are small they have to be to exchange wastes and nutrients
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all cells have an outer membrane
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called the plasma membrane
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The plasma membrane encloses a semi-fluid substance called
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Cytoplasm
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The plasma membrane regulates
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what enters and exits the cell
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Cytoplasm
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carry on chemical reactions and the genetic material provides information needed for growth and reproduction
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Cell theory
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the concept that all organisms are composed of cells and that cells come from preexisting cells are the two tenets of the theory
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Prokaryotic Cells
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organisms from domains Archaea and Bacteria date back to the first cells on earth 3.5 million years ago.
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Prokaryotic cells are
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much smaller then Eukaryotic cells and much simpler they reproduce quickly
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Bacterial Structure
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1 Plasma wall which surrounds the cytoplasm
2 Cell wall maintains cell shape 3. capsule is a prot6ective layer of polysaccharides out side the cell wall |
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Bacteria cell continued
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4 nucleoid location of the bacterial chromosome ---DNA
5 Ribosome site of protein synthesis 6. Flagella tail like appendage for motion |
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Bacteria cell continued
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Bacteria cell continued
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4 nucleoid location of the bacterial chromosome ---DNA
5 Ribosome site of protein synthesis 6. Flagella tail like appendage for motion |
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Bacteria cell continued
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7. Fimbriae small bristle like fibers help cell to attach to a surface.
8. Conjugation pili rigid tubular structure to allow DNA to pass from cell to cell |
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The Plasma membrane
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marks the boundary between the inside and outside of a cell it acts as a gate keeper regulating the passage of molecules and ions into and out of the cell
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In both prokoryotes and eukaryotes the plasma membrane is
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a phospholipid bilayer with embedded proteins the polar (hydorphilic) heads of the phospholipids are orientated in two directions-interior and exterior the nonpolar tail (hydrophobic) face toward each other
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Channel proteins
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form tunnel across the entire membrane, allowing only one or a few types of specific molecules to simply move across the membrane
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Transport protiens
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also involved in the passage of molecules and ions through the membrane, they often combine with a substance and help it move across the membrane
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Cell recognition Proteins
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glycoproteins among other functions these proteins enable our body to distinguish between our own cells and those of other organisms
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Receptor Proteins
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has a shape that allows a specific molecule, called a signal molecule to bind with it this binding allows the protein to change shape and make a cellular response
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Enzymatic proteins
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some plasma membrane proteins are enzymatic proteins that directly participate in metabolic reactions
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Junction proteins
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form junctions between cells this assists cell-to-cell adhesion and communication
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Eukaryotic Cells
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protists, fungi, plants, and animals are composed of these cells
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Eukaryotic Cells
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Have a Nucleus that is membrane bounded and houses DNA
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organelles
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differ in structure and function all the molecules necessary to perform a particular are concentrated inside the organelle
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The nucleus and the ribosomes
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the nucleus communicates with the ribosomes, which are small particles that synthesize proteins coded for by DNA located within the chromosomes
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Organelles of the endomembrane system (ES)
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Each of these organelles has its own particular set of enzymes and produces its own products the products are carried between the ES organelles by transport vesicles small membranous sacs the isolate the products from the cytoplasm
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The energy-related organelles
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the energy-related organelles--chloroplasts in plant cells and mitochondria in animal cells are more self contained than those of the ES they even contain DNA and process ribosomes that resemble prokaryotic cells
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The cytoskeleton
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is a lattice of protein filaments and tubules that maintains the shape of the cell and assists in the movement of organelles
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The Nucleus
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because of its large size is one of the most notable structures of eukaryotic cells the nucleus contains chromatin
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Chromatin is in
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a semifluid nucleoplasm and is a network of strandsjust before the cell divides chromatin condenses and coils to become rod -like structures of DNA
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Nuclelus
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a dark structure with in the nucleus--another form of RNA is produced here another form of protien joins the rRNA to make ribomes
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The Nucleus is separated
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from the cytoplasm by a double membrane of phosphlipids know as the nuclear envelope
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Located through out the nuclear envelope are
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nuclear pores which are sufficient to permit the passage of ribosomal subunits a mRNA out of the nucleus and protiens into the nucleus
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Chromatin is composed of
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DNA, protein, and some RNA it creates messenger RNA or mRNA which translates to the polypiptide
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Ribosomes
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found in both prokaryotes and eukaryotes the are composed of two subunits one large one small Ribosomes are sites of protein synethesis
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Some ribosomes are attached to
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the endoplamic reticulum (ER) an organelle of the endomembrane system after the ribosome binds to the receptor at the ER the polypetide being enters the lumein (interior) of the ER where it assumes its final shape
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Endomembrane system
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consists of the nuclear envelope, the membranes of the endoplasmic reticulum and many small sacs called vesilces
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transport vesicles
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carry molecules from one part of the system to another
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Endoplamic Reticulum
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consists of a complicated system of membranous channels and saccules (flattened vesicles) it is physically continuous with the outer membrane of the nuclear envelop
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Rough ER
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is studded with ribosomes on the side that faces the cytoplasm therefore is able to synthesize polypeptides
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Smooth ER
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which is continuous with rough ER does not have attached ribosomes Smooth ER synthesis lipids such as phosopholipids and steroids the function is dependent on the cell
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Golgi Apparatus
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consists of 3 to 20 slightly curved flattened saccules resembling pancakes thouhgt to be a transfer station
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Secretion
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outgoing transport vesicles that proceed to the plasma membrane where they discharge their contents called secretion
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Lysosomes
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produced by the Golgi apparatus, that digest molecules and even parts of the cell itself
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Vacuoles
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like vesicles are membranous sacs, but vacuoles are larger then vesicles.in some protists vacuoles are very specialized Plant cell contain them as well for pigment and toxic molecules
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Energy-related Organelles
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Chloroplasts use sole energy to synthesize carbohydrates.
Mitochondria break down carbohydrates to produce ATP |
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Choroplasts
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found in plants and algae produce carbohydrates by photosynthesis have a 3 membrane system
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Stroma
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a large inner space in the membrane of chloroplasts contains a concentrated mixture of enzymes and thylakoids
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Thylakoids
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are formed from the third membrane
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Granum
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is a stack of thylakoids the lumens of the thylakoids sacs form an compartment called the thylakiod space which pigments here capture the solar energy that synthesis carboyhydrates in the stroma
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Mitochondria
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have a double membrane the inner membrane is highly convoluted into folds called cristae. this inner membrane encloses the matrix
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Matrix
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contains a highly concentrated mixture of enzymes that assists in the breakdown of Carbohydrates and other molecules---which involves the cytoplasm called cellular respiration
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Cytoskeleton
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is a network of interconnected protein filaments and tubules that extend from the nucleus to the plasma membrane in eukaryotic cells
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The cytoskeleleton maintains cell shape
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and along with motor proteins allow cell organelles to move
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Microtubules
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small hollow composed of 13 long chains of tubulin dimers act as track for organelles to move microtuble assembly is controlled by the centrosome an microtubles organizing center
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Intermediate Filiments
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are intermediate in size to actin filiments and microtubules rope like assemblies of protein they form supports for both the nucleus and plasma membrane
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Actin Filaments
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consists of two chains of globular actin monomers twisted about one another in a helical manner to form a long filament--they support the cell forming a dense complex web
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Motor Proteins
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myosin--interacts with actin
kinesin, dynein these two move along on microtubules help organelles to move |
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Centrioles
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are short cylinders with a 9+0 pattern of microtubule triplets that is nine sets of triplets occur in a ring
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Cilia and flagella
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are hair like projections that can either move stiffly like an oar, or undulate , like a whip
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All plant cells have a cell wall
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a primary cell wall contains cellulose fibrils and noncellulose substances that allow the wall to stretch--some plants have a secondary cell wall to add strenght
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In a plant living cells are connected by plasmodesmata
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numerous narrow, membrane-lined channels that pass through the cell wall
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Extracellular Matrix (ECM)
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is a meshwork of fibrous proteins and polysaccharides in close association with the cell that produced them collagen and elastin are proteins here
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Juctions between cells
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adhesion junctions
tight junctions gap junctions |
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adhesion junctions
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internal cytoplasmic plaques, firmly attached to the cytoskeleton within each cell--results in a sturdy flexible sheet
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tight junctions
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adjacent cells a closely joined by plasma membrane protiens
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gap junction
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allows cells to communicate, formed by two identical plasma channels lined by 6 plasma membrane proteins allow the junction to open and close
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