Term
| why is the cell membrane called a "mosaic"? |
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Definition
| because of the different types of proteins insterspersed with the phospholipid bilayer |
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Term
| what are two kinds of proteins in the cell membrane, and what's the difference between them? |
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Definition
| peripheral proteins are attached to the cell membrane but don't penetrate. integral proteins penetrate the cell membrane. |
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Term
| what limits the amount of glucose that gets into a cell? |
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Definition
| how many transport proteins there are in the cell membrane |
|
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Term
| how much energy do the transport proteins for glucose use? |
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Definition
| none - it's a nonenergetic process |
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Term
| why aren't O2 molecules stopped by the phospholipid bilayer? |
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Definition
| most of the phospholipid bilayer consists of fatty acid chains, which are hydrophobic and will interact with hydrophobic molecules. O2 is hydrophobic (nonpolar) and as such can get right through by diffusion. |
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Term
| define: concentration gradient |
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Definition
| the difference between the concentration of a molecule inside the cell and outside of it |
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Term
| why can't glucose pass through the cell membrane by itself? (2) |
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Definition
1) it's too big
2) it's hydrophilic (from the hydroxyl groups) - it gets stopped by the fatty acid chains in the phospholipid bilayer. |
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Term
| in a blood concentration reading, what ion would you expect to have a greater concentration inside the cell, and which a greater concentration outside the cell? |
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Definition
| Na+ has a greater concentration outside, and K+ has a greater concentration inside. |
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Term
| how could Na+ diffuse into the cell? why does it need this method? |
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Definition
| it uses protein channels to diffuse in; it's hydrophilic (charged) and therefore can't get in by itself. |
|
|
Term
| what is the sodium-potassium ATPase pump? |
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Definition
| a transport protein that pumps Na+ out of the cell when it tries to enter and K+ back in when it tries to get out |
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Term
| why does the sodium-potassium ATPase pump need energy? |
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Definition
| it opposes the natural force of diffusion |
|
|
Term
| where does the sodium-potassium ATPase pump get its energy from? |
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Definition
| the breakdown of ATP into ADP (released energy from breaking one of the phosphate groups off) |
|
|
Term
| where does ATP store energy? |
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Definition
| in the bonds between the three phosphate groups |
|
|
Term
| what is the second ability of ATPase? |
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Definition
| other than being a sodium-potassium pump, it's the enzyme that breaks down ATP, supplying its own energy |
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Term
| how does embryonic development provide an example of cell-cell recognition? |
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Definition
| like cells match with like cells at the embryo develops |
|
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Term
| what do membrane proteins have to do with cell-cell recognition? |
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Definition
| the membrane proteins differ for different types of cells |
|
|
Term
| how does a hormone affect a cell? |
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Definition
| it binds to its corresponding receptor protein |
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|
Term
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Definition
| general term for a molecule that binds to a protein receptor in the cell membrane |
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Term
| what are the different types of cell membrane proteins? (5) |
|
Definition
1) enzymes
2) transport proteins (facilitated diffusion)
3) protein channels
4) cell-cell recognition
5) receptor proteins |
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|
Term
| define: nonpenetrating solute |
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Definition
| a substance dissolved in a solution (like, say, sodium in water) that can't pass a membrane, while the water CAN |
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|
Term
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Definition
| measure of the concentration of a nonpenetrating solute (like [Na+](aq)) |
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Term
| adding what to the blood will cause crenation? |
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Definition
| Na+ -- the blood will become hypertonic, and water will drain from the cells to dilute it, causing them to shrivel |
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Term
| what are two ways water gets through the phospholipid bilayer? which is the one most molecules use? |
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Definition
| a small amount of water can get through the phospholipid bilayer on its own because it's such a small molecule. But most of it gets through via special protein channels called aquapores |
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|
Term
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Definition
| drinking too much water -- will cause the inside of cells to be hypertonic relative to the outside, cause blood to flow in, and they explode |
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|
Term
| what aspect of the cell increases when you decrease cell density? (for instance by adding new molecules) |
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Definition
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Term
| why is the cell membrane's makeup called "fluid mosaic model"? |
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Definition
| it's not a solid structure - it has a lot of parts, and they move around (mostly because of the fluid nature of the cholesterol molecules) |
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|
Term
| what are contained within the cytoplasm? |
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Definition
|
|
Term
| what sort of ribosome would produce insulin? |
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Definition
| a bound ribosome (attached to the rough ER) |
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|
Term
| where does protein synthesis/production occur? |
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Definition
|
|
Term
| why would ovary cells have a lot of smooth ER? |
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Definition
| ovaries produce a LOT of steroids (like hormones steroids) and so need a lot of smooth ER, which produce steroids |
|
|
Term
| what are the functions of smooth ER? (3) |
|
Definition
1) steroid synthesis (also some other lipids)
2) detoxification
3) storage for calcium ions (in muscle) |
|
|
Term
| what two kinds of cells would be likely to have a lot of smooth ER, and why? |
|
Definition
- liver, because smooth ER detoxes and that's where most detoxification happens in the body
- ovary cells, because they produce a lot of hormones, which are steroids; and steroids are produced in the smooth ER |
|
|
Term
| what is the function of rough ER? |
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Definition
| it modifies the proteins that the ribosomes produce |
|
|
Term
| what are the two most common things the rough ER does to a protein? |
|
Definition
1) adds a carbohydrate molecule (making it a glycoprotein)
2) package the protein into a vesicle (a little membrane-bound sac) |
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|
Term
| where do proteins contained in vesicles go after being released from the rough ER? |
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Definition
| the golgi complex - go in the convex end, are modified (cutting a little bit off), packaged in a secretory vessel, which fuses into the cell membrane and undergoes exocytosis |
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|
Term
|
Definition
| the secretory vessel fuses to the cell membrane and integrates into it, allowing the packaged protein to be secreted outside the cell and adding to the cell membrane structure |
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|
Term
| what is a hydrolitic enzyme and where are they contained? |
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Definition
| a very powerful enzyme that breaks things down - contained inside the lysosomes |
|
|
Term
| what is the pH of a lysosome like? |
|
Definition
| acidic - around 5 or so. the outside cytoplasm is basic. the reason lysosomes have to be acidic is because the hydrolitic enzymes are active in acidic environments |
|
|
Term
| what are the functions of the lysosomes? (3) |
|
Definition
1) phagocytosis
2) programmed cell death
3) lipid macromolecule breakdown |
|
|
Term
|
Definition
| when a white blood cell (neutrophil) meets a bacterial cell it envelops it and internalizes it into its cell structure - enters the cytoplasm. Then the bacterial cell is broken down by the lysosomes. |
|
|
Term
| what causes taysachs disease? |
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Definition
| there aren't enough enzymes in the lysosomes, so the lipids in the neurons of the brain don't undergo programmed cell death, so there is an overload |
|
|
Term
| why do mitochondria have christae? |
|
Definition
| to increase the membrane area |
|
|
Term
| what are the components of chromosomes? |
|
Definition
| mostly DNA, some proteins. |
|
|
Term
| where are ribosomes assembled? |
|
Definition
|
|
Term
|
Definition
| ribosomal RNA - makes up ribosomes |
|
|
Term
| what is the nuclear envelope composed of? |
|
Definition
| TWO phospholipid bilayers (double membrane) |
|
|
Term
| how to ribosomes get past the nuclear envelope? |
|
Definition
| travel through nuclear pores |
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|
Term
| what are the three structures that make up the cytoskeleton? (smallest to largest) |
|
Definition
microfilaments
intermediate filaments
microtubules |
|
|
Term
match the protein to the structure:
microfilaments, intermediate filaments, microtubules
keratin, tubulin, actin |
|
Definition
microfilaments: actin
intermediate filaments: keratin
microtubules: tubulin |
|
|
Term
| what are the two basic functions of the cytoskeleton? |
|
Definition
|
|
Term
| where are three places microtubules provite motility, and what form do they take? |
|
Definition
| cilia in the throat and the fallopian tubes transport mucuous and eggs, respectively; and flagella in sperm. |
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|
Term
| what is coupling (in a chemical reaction context)? |
|
Definition
| exergonic reactions produce energy that endergonic reations need - like redox reactions |
|
|
Term
| what are three things that are produced during glycolysis? |
|
Definition
1) 2ATP
2) 2 pyruvate
3) NADH |
|
|
Term
| what is the feeder molecule that starts off the krebs cycle? the electron transport chain? |
|
Definition
krebs cycle: pyruvate
electron transport chain: NADH |
|
|
Term
| what is a very common componant of the molecules in the electron transport chain? |
|
Definition
|
|
Term
| what are two common locations for Fe in the body? |
|
Definition
- hemoglobin
- the molecules of the electron transport chain |
|
|
Term
| what is the final electron receptor in the electron transport chain? |
|
Definition
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