Chapter 3

Question 0

Functions of plasma membrane proteins: channels

Answer 0

water-filled passageway

• highly selective (water soluble can enter, very small)
• can open or close

Question 1

cell membrane: structure

Answer 1

phospholipid bilayer

• cholesterol - stability
• proteins:
  
  • integral - spanning entire membrane)
  • peripheral - sticking out

Question 2

Functions of plasma membrane: carrier molecules

Answer 2

transport substances in or out that are not free to pass

- only open to one side at a time (not ECF and ICF at the same time)

Question 3

functions of plasma membrane: membrane bound enzymes

Answer 3

control chemical reactions

ex. Ache

Question 4

functions of plasma membrane: receptor sites

Answer 4

can bind with extracellular signals

• use lock and key theory (will bind if messenger fits with receptor)
• have to be complementary
• ex. prolactin knows to bind to breast cells cause they fit

Question 5

functions of plasma membrane: cell adhesion molecules

Answer 5

grip other cells

• allows cells to form tissues and to stick to various things (ex. WBC)
• protrude from plasma membrane
• ex. Cadherin (velcro)

Question 6

functions of plasma membrane: ID tags

Answer 6

• proteins often with CHOs (glycoproteins)
• helps cells to recognize of the same type
• prevent overgrowth of tissue - “contact inhibition” (once mitosis is filled in all the areas, they stop growth)

Question 7

passive

Answer 7

does NOT require ATP

- relies on molecular motion

Question 8

Active

Answer 8

requires ATP

Question 9

Unassisted

Answer 9

does not require help/assistance

Question 10

assisted/carrier mediated

Answer 10

needs a carrier molecule (needs help)

Question 11

diffusion

Answer 11

• unassisted
• the movement of molecules from a high concentration to a low concentration
• molecules move DOWN their concentration gradient

Question 12

Osmosis

Answer 12

• unassisted
• diffusion of water DOWN its concentration gradient
• high concentration to a low concentration
• osmotic pressure = pulling
• water being pulled toward the higher solute concentration

Question 13

tonicity

Answer 13

measure of solute concentration

- referring to the solute concentration in the ECF

Question 14

isotonic

Answer 14

ICF and ECF solute concentration is =

Question 15

hypotonic

Answer 15

the ECF has a lower concentration of solutes than the ICF

- water is drawn towards higher solute concentration

Question 16

Hypotonic: The osmotic pressure is ________ the cell; therefore water will tend to ______ the cell due to osmosis

Answer 16

higher in

enter

Question 17

hypertonic

Answer 17

the ECF has a higher concentration of solutes than the ICF

Question 18

hypertonic: the osmotic pressure is _________ the cell; therefore water will tend to ______ the cell due to osmosis

Answer 18

higher outside

leave

Question 19

filtration

Answer 19

the movement of substances through a membrane as a result of a higher hydrostatic of one side of the membrane
- ex. coffee (directing hydrostatic pressure through membrane -> water pushes coffee grounds through filter into the cup)

Question 20

example of filtration in the body

Answer 20

cells are filtered out of the blood stream

Question 21

carrier mediated transport

Answer 21

can be active or passive

Question 22

characteristics that determine the kind and amount of material that can be transferred across the membrane are_______, ________, and ________

Answer 22

specificity
saturation
competition

Question 23

specificity

Answer 23

shapes match (carrier molecule for amino and another carrier molecule for glucose - shapes have to match)

Question 24

satuaration

Answer 24

``` transport maximum (TM) - mini van analogy - can't carry anymore no matter how much it is flooded (wine analogy) ```

Question 25

competition

Answer 25

similar molecules compete

Question 26

facilitated diffusion

Answer 26

substances move from a HIGHER concentration to a LOWER concentration - requires carrier molecule - no ATP - ex. GLUT

Question 27

does facilitated diffusion require ATP?

Answer 27

No

Question 28

active transport

Answer 28

moves a substance UP its concentration gradient by using a carrier molecule - requires ATP ex. Na+/K+ pump

Question 29

vesicular transport: 2 types

Answer 29

endocytosis | exocytosis

Question 30

endocytosis

Answer 30

import

Question 31

exocytosis

Answer 31

export

Question 32

Endocytosis: Phagocytosis

Answer 32

cell-eating - ATP required - occurring all the time

Question 33

Endocytosis: Pinocytosis

Answer 33

cell-drinking

Question 34

Exocytosis

Answer 34

release of secretory products | " how do we get things out of the cell?"

Question 35

membrane potential

Answer 35

difference in charges between ICF and ECF or the separation of opposite charges across plasma membrane

Question 36

membrane potential is measured in ______

Answer 36

mV

Question 37

resting membrane potential

Answer 37

constant membrane potential present in cells at rest - separation of charges in a cell at rest - nerve cell RMP = -70 mV

Question 38

The cell membrane is more permeable to ___ than to ____

Answer 38

K+ | Na+

Question 39

K+ leaks/diffuses out at a ______ rate

Answer 39

faster

Question 40

effect of sodium/potassium pump on membrane potential: pumps ______ in and ________ out

Answer 40

2K+ | 3Na+

Question 41

passive ______ and the active ________ work together to establish the RMP

Answer 41

diffusion | Na+/K+ pump

Question 42

nerve and muscle cells are excitable cells and have the ability to __________ in their membrane potential when excited

Answer 42

produce rapid changes | - this gives us nerve impulses and muscle contractions

Question 43

proteins that span the whole membrane are called what?

Answer 43

integral

Question 44

where are the peripheral proteins

Answer 44

they stick out

Question 45

simply state how active transport is different from passive transport

Answer 45

active transport requires ATP and passive transport does not use ATP

Question 46

is osmosis passive or active

Answer 46

passive

Question 47

define diffusion

Answer 47

the movement of molecules from a high concentration to a low concentration

Question 48

define osmosis

Answer 48

high concentration of water --------> low concentration of water

Question 49

cells in a hypertonic solution will _____ water as a result of osmosis

Answer 49

lose

Question 50

water molecules move _____ the higher osmotic pressure

Answer 50

toward

Question 51

tonicity refers to the solute concentration in the ___

Answer 51

ECF

Question 52

in carrier mediated transport, we talk about specificity of the molecules. What does this mean?

Answer 52

shapes have to match - lock and key method

Question 53

what is TM

Answer 53

transport maximum | minivan analogy

Question 54

how does the example of TM in class about glucose in the urine demonstrate the above

Answer 54

if there is too much glucose in the urine, TM will grab the g molecules and pull them back into the blood stream

Question 55

membrane potential is defined as

Answer 55

difference in charges between ICF and ECF or the separation of opposite changes across plasma membrane

Question 56

what two cell types are excitable

Answer 56

nerve and muscle cells | - have ability to produce rapid changes in their membrane potential when excited

Question 57

resting membrane potential is defined as

Answer 57

constant mp present in cells at rest

Question 58

resting potential is about ____ mV for the normal cell

Answer 58

-70

Question 59

so that means that K+ wants to diffuse _____ and Na+ wants to diffuse ___

Answer 59

out | in

Question 60

how many Na+ are pumped

Answer 60

3 out

Question 61

how many K+ are pumped

Answer 61

2 IN

Question 62

the cell membrane is leakier to ___ than to ___

Answer 62

K+ | Na+