ch. 5 structure and function of plasma membranes

Question 1

what is the fluid mosaic model?

Answer 1

membranes consist of a bilateral of phospholipids in which globular proteins are inserted

Question 2

what is a glycoprotein?

Answer 2

a protein with carbohydrate attached

Question 3

what are the four components of cell membranes?

Answer 3

phospholipid bilayer, transmembrane proteins, interior protein network, cell surface markers

Question 4

what holds together the two layers of the phospholipid bilayer?

Answer 4

hydrogen bonds

Question 5

what can move through the cell membrane?

Answer 5

individual phospholipids and unanchored proteins

Question 6

what makes the cell membrane less fluid?

Answer 6

saturated fatty acids

Question 7

what temps can make the cell membrane more fluid?

Answer 7

warm

Question 8

what are peripheral membrane proteins?

Answer 8

anchored to a phospholipid in one layer of the cell membrane; possess non-polar domains that are inserted in the lipid bilayer; can move through one layer of the bilayer

Question 9

what are integral membrane proteins?

Answer 9

proteins that span the lipid bilayer (transmembrane proteins), they have polar domains embedded in the hydrophobic regions of the lipid bilayer, polar domains protrude from both sides of the bilayer

Question 10

what do all integral proteins possess at least one of?

Answer 10

a transmembrane domain

Question 11

what is a transmembrane domain?

Answer 11

region of the protein containing hydrophobic amino acids (spans the lipid bilayer)

Question 12

what can form a b-barrel?

Answer 12

b-sheets

Question 13

what is a b-barrel?

Answer 13

polar interior, allows water and other small polar molecules to pass through the membrane

Question 14

what do carrier proteins do?

Answer 14

bind to a specific molecule to facilitate its passage

Question 15

what molecules do channel proteins let through?

Answer 15

polar molecules

Question 16

what does hypertonic mean?

Answer 16

it has a high concentration of dissolved molecules

Question 17

what does isotonic mean?

Answer 17

same

Question 18

what does active transport need to happed?

Answer 18

energy and carrier proteins

Question 19

what are uniporters?

Answer 19

carrier proteins that move one molecule at a time

Question 20

what are symporters?

Answer 20

carrier proteins that move two molecules in the same direction

Question 21

what are antiporters?

Answer 21

carrier proteins that move two molecules in opposite directions

Question 22

what is the sodium potassium pump?

Answer 22

an active transport mechanism that uses an antiporter to move three Na+ out of the cell and two K+ into the cell

Question 23

what is the sodium potassium pump used for?

Answer 23

to depolarize the neurons in the nervous system

Question 24

what is coupled transport?

Answer 24

uses the potential energy released by diffusion to actively transport a different molecule (uses a symporter)

Question 25

what is bulk transport?

Answer 25

the movement of large amounts of materials

Question 26

what is endocytosis?

Answer 26

bulk transport where substances are moved into the cell

Question 27

what is exocytosis?

Answer 27

bulk transport where substances are moved out of the cell

Question 28

what is phagocytosis?

Answer 28

endocytosis where the cell takes in particulate matter

Question 29

what is pinocytosis?

Answer 29

endocytosis where the cell takes in fluid

Question 30

what is receptor mediated endocytosis?

Answer 30

endocytosis where specific molecules are taken in after they bind to a receptor