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Flashcards in Chapter 5 Deck (53)
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1
Q

what is a big function of the plasma membrane?

A

controlling movement in and out of the cell

2
Q

list three small molecules that can move easily in and out of membranes

A

water, O2, and H2

3
Q

if a substance is larger or has a different polarity than the cell membrane, what does the cell use to help it in or out?

A

special proteins

4
Q

what are the 4 components of the cell membrane?

A
  1. phospholipid bilayer
  2. embedded proteins: integral and peripheral
  3. cholestrol
  4. glycoproteins and glycolipids
5
Q

what is a peripheral protein?

A

proteins embedded in the top or bottom of the phospholipid bilayer, don’t go all the way through, nonpolar

6
Q

what is an integral protein?

A

proteins that go all the way through the phospholipid bilayer, also called transmembrane proteins, some solid, some hollow, have polar and nonpolar regions

7
Q

what do the glycoproteins attach to?

A

the embedded proteins

8
Q

what are the two parts of phospholipids?

A

POLAR head, and NONPOLAR tail

9
Q

what is the spherical structure formed by the polar ad nonpolar properties of phospholipids?

A

micelles

10
Q

what are the 5 functions of membrane proteins?

A
  1. structure; integrity
  2. transport; channels for molecules
  3. self-identity; recognized as you or not you, RBC’s blood type
  4. communication; send signals and communicate with cell neighbors
  5. cellular movement (external structures); flagella and cilia are made of microtubule proteins
11
Q

what are the two main categories of membrane proteins?

A

integral and peripheral

12
Q

what is the function of peripheral proteins?

A

communication and self-identity

13
Q

what is the function of integral proteins?

A

transport, some structural support

14
Q

what is the importance of the plasma membrane?

A

defines cell boundaries, regulates movement in and out

15
Q

what are the functions of the plasma membrane?

A

protection, self-recognition, communication

16
Q

what is a solvent? definition and example

A

something that dissolves other things, water

17
Q

what is a solute? definition and example

A

something that gets dissolved, NaCl (in water), sugar

18
Q

what is a solution?

A

a solvent and its dissolved solute, salt water, sweet tea

19
Q

what is diffusion?

A

movement of solutes within a solution down the concentration gradient

20
Q

what is Brownian motion?

A

the constant movement, jiggling, and crashing of solutes in response to a concentration gradient

21
Q

the more concentrated a solution is, will there be more or less solute collisions?

A

more

22
Q

how does the concentration gradient of solutes move?

A

from high solute concentration to low solute concentration, seeking and eventually achieving equilibrium

23
Q

what happens to the solutes one equilibrium is reached?

A

there is no more net movement

24
Q

when two solutions have different concentrations with a membrane separating them, what three conditions are there?

A

hypertonic, hypotonic, and isotonic

25
Q

describe a hypertonic solution

A

very concentrated, more solutes than the other solution

26
Q

describe a hypotonic solution?

A

not as concentrated, fewer solutes than the other solution

27
Q

describe an isotonic solution?

A

both solutions have equal solute concentrations

28
Q

how do solutes move?

A

down the solute concentration gradient, from high to low solute concentration, hypertonic to hypotonic

29
Q

define selective permeability?

A

the ability of a membrane to control whether or not a solute can move across

30
Q

write the formula for rate of diffusion

A

rate = distance/time

31
Q

what 6 factors determine the rate of diffusion?

A
  1. the higher/steeper the concentration gradient = faster diffusion, slows as equilibrium is approached
  2. cell surface area, bigger = faster diffusion (to a certain point until too big to reach center of cell)
  3. travel distance, farther distance = slower diffusion, inverse relationship
  4. temperature, higher = faster diffusion b/c of Brownian motion, direct relationship
  5. molecule size, bigger = slower, needs more help
  6. charge
32
Q

what is the diffusion of water, typically across a membrane called?

A

osmosis, and its rules are hella weird

33
Q

when other solutes can’t move, what molecule can and will?

A

water, it wants to dissolve everything

34
Q

what is water’s concentration gradient?

A

low SOLUTE to high SOLUTE concentration (it wants to dissolve everything), and high WATER concentration to low WATER concentration, so it is still passive transport

35
Q

what does the direction of osmosis depend on?

A

water and solute concentration

36
Q

what type of solution do cells WANT to be in?

A

isotonic

37
Q

do isotonic solutions occur often?

A

no :(

38
Q

what happens when a cell is placed into a hypertonic solution?

A

if solutes can’t cross the membrane, water leave the cell to dissolve outside solutes, and cell shrivels

39
Q

what is cell shriveling called in an animal cell?

A

crenation

40
Q

what is cell shriveling called in a plant cell?

A

plasmolysis, central vacuole will shrink, and cytoplasm will pull away from cell wall to fill the space

41
Q

what happens when a cell is placed into a hypOtonic solution?

A

if solutes can’t cross the membrane, water rushes into the cell to dissolve inside solutes, and cell swells and can burst

42
Q

what is it called when an animal cell swells and bursts?

A

lysis

43
Q

can a plant cell burst? why or why not?

A

no, the cell wall won’t allow it

44
Q

what is it called when a plant cell swells?

A

turgid

45
Q

what does a plant cell look like when it’s turgid?

A

very full, cell wall may give a little bit, central vacuole is full, cytoplasm is pushed up against cell wall

46
Q

what happens to red blood cells in a hypertonic solution of 10% salinity?

A

crenation, water leaves cell, cells can’t travel through bloodstream, blood clots form
ex. dehydraton

47
Q

what happens to red blood cells in a solution of 0.9% salinity?

A

they are happy plump donuts!

48
Q

what happens to red blood cells in a solution of 0% salinity of distilled water?

A

water rushes in, cells swell and can burst, lysis

49
Q

what solution is given in IV’s in the hospital?

A

lactated ringer’s, 0.9% salinity

50
Q

what are three ways that cells deal with nonisotonic environments?

A
  1. extrusion
  2. isoosmotic regulation
  3. turgor pressure
51
Q

describe extrusion

A

used by protists, which are almost always in a hypotonic environment, contractile vacuoles act like pumps, pumping excess water into a vacuole that is then expelled and dumped into surrounding environment

52
Q

describe isoosmotic regulation

A

we do this! kidneys control how much water the body loses when you pee, if dehydrated, water is kept in body and pee is clear, if not dehydrated, some water can be lost, and pee approaches clear

53
Q

describe turgor pressure

A

plant cells use this, they store excess water in their central vacuole when in a hypotonic environment