chapter 5- membranes

Question 1

control the flow of substances into and out of a cell

Answer 1

selectively permeable

Question 2

what are the structures of a cell membrane

Answer 2

phospholipid
proteins
cholesterol
carbohydrate

Question 3

what do proteins do in a cell membrane?

Answer 3

transport
enzymes
attachment
receptors
junctions
glycoproteins

Question 4

what does cholesterol do in a cell membrane

Answer 4

-maintains fluidity of membrane

-prevents packing of phospholipids and slows movement

Question 5

carbohydrate structure of cell membrane

Answer 5

glycolipif and glycoprotein

Question 6

help substances cross the membrane

Answer 6

transport

Question 7

speed up chemical reactions

Answer 7

enzymes

Question 8

_______________ to the extra cellular matrix and to cytoskeleton

Answer 8

attachment

Question 9

bind to specific molecule

Answer 9

receptors

Question 10

connections between cells

Answer 10

juntions

Question 11

cell identity/recognition

Answer 11

glycoproteins

Question 12

passive transport

Answer 12

no cellular energy required

Question 13

-movement of substances from high concentration to low concentration

-tendency for particles to spread into open space (in or out of cell)

-no cellular energy required

Answer 13

diffusion

Question 14

example of diffusion

Answer 14

oxygen into cell
carbon dioxide out of cell

Question 15

movement of water from high concentration to low concentration across a membrane

• the solution is what’s moving, not the solutes in it
• water goes wherever they are more solutes

Answer 15

osmosis

Question 16

solution with a solute concentration lower than that of the cell

Answer 16

hypotonic

Question 17

a solution with a higher solute concentration than that of a cell

Answer 17

hypertonic

Question 18

solute concentration of environment and of a cell are equal

Answer 18

isotonic solution

Question 19

what happens to an animal cell placed in solution with higher solute concentration than the cell (hypertonic)

Answer 19

it shrivels

Question 20

what happens to an animal cell when it is placed in a solution with lower solute concentration thst the cell (hypotonic)

Answer 20

it swells and may burst

Question 21

what happens to a plant cell when placed in a hypotonic solution with lower solute levels

Answer 21

plant cell is turgid (very firm) and healthy. the cell swells but the pressure of cell wall pushes back and prevents from absorbing too much water and bursting like an animal cell would

Question 22

what happens when a plant cell is placed in isotonic solution with equal concentration of solutes?

Answer 22

the cell is flaccid (limp) and may wilt

Question 23

what happens when a plant cell is placed in hypertonic environment and there are higher solute levels outside the cell

Answer 23

the plant cell loses water and cell membrane pulls away from the cell wall and plant can die. (plasmolysis)

Question 24

-movement of cells against concentration gradient using transport protein

-requires cellular energy

• na+ / k+

Answer 24

active transport

Question 25

-large products of cell (proteins lipids waste) move out of cell through a transport vesicle

-required cellular energy

Answer 25

exocytosis

Question 26

bringing larger substances against concentration gradient

Answer 26

endocytosis

Question 27

-cell eating macromolecule

-enters cell thru a vacuole

Answer 27

phagocytosis

Question 28

-cell drinking

• liquid enters cell through vesicle

Answer 28

pinocytosis

Question 29

-specific molecule like a hormone binds to receptor

• enter through a vesicle

Answer 29

receptor mediated