Membranes

Question 1

plasma membrane

Answer 1

outer boundary of cell that separates from the world

Question 2

phosphoglycerides

Answer 2

diacylglycerides with small functional head groups linked to the glycerol backbone by phosphate ester bonds

Question 3

sphingolipids

Answer 3

ceramides formed by the attachment of sphingosine to fatty acids

Question 4

glycolipids

Answer 4

receptors for extracellular ligands

Question 5

what kinds of lipids are on the cytosolic leaflet of pm?

Answer 5

phosphatidylserine
phosphatidylethanolamine
phosphatidylinositol

Question 6

what kind of lipids are on the exoplasmic leaflet of pm?

Answer 6

sphingomyelin

phosphatidylcholine

Question 7

cholesterol

Answer 7

smaller and less amphipathic lipid that is only found in animals

Question 8

N-glycosidic linkage

Answer 8

attached to asp

Question 9

O-glycosidic linkage

Answer 9

attached to ser or thr

Question 10

passive transport

Answer 10

does not require energy

Question 11

active transport

Answer 11

requires energy

Question 12

facilitated diffusion

Answer 12

diffusion facilitated by a protein transporter

Question 13

how can molecules passively diffuse through membranes?

Answer 13

must move from high concentration to low concentration

substance can dissolve in lipid bilayer or pass through pore

Question 14

hypotonic

Answer 14

net water gain; cell swells

Question 15

hypertonic

Answer 15

net water loss; cell shrinks

Question 16

isotonic

Answer 16

no net loss or gain of water

Question 17

aquaporins

Answer 17

specialized channels for H2O transport

Question 18

voltage-gated channels

Answer 18

open vs. closed based on differences in ionic charge between the inside and outside of cell

Question 19

ligand-gated channels

Answer 19

open vs. closed based on a ligand binding to the channel (conformational change)

Question 20

opening/closing of eukaryotic K+ channel

Answer 20

once opened more than 10 million K+ ions can pass through per second
after open for a few milliseconds, movement of ions is stopped (inactivation)

Question 21

functions of cyctic fibrosis

Answer 21

Cl- channel; transportes bicarb ions; blocks Na+ channels

Question 22

facilitative transporters

Answer 22

transmembrane proteins that bind a substance and transport it across the membrane

Question 23

which direction do facilitative transporters transport molecules in?

Answer 23

either direction

Question 24

sodium potassium pump moves ____ inside and ____ outside

Answer 24

potassium; sodium

Question 25

how does sodium potassium pump work?

Answer 25

-sodium binds to the transport protein on inside of cell
-ATP is hydrolyzed and the released P binds to transport protein
-binding of P changes transporter’s configuration and affinity for sodium; sodium is released to outside of cell
-potassium binds to pump
-pdissociates
pump resumes original conformation
potassium released into cytoplasm

Question 26

in the sodium/glucose cotransporter, which directions to the molecules move in?

Answer 26

the same direction

Question 27

how many sodium ions are transported for every glucose molecule in the sodium/glucose transporter

Answer 27

2

Question 28

dendrites

Answer 28

receive incoming information

Question 29

cell body

Answer 29

contains nucleus and the metabolic center of the cell

Question 30

axon

Answer 30

long extension for conduction outgoing impulses