Exam 2 Part 1

Question 1

small, non-polar molecules

Answer 1

O2, CO2, N2, steroid hormones

small enough to pass through membrane

Question 2

small, uncharged polar molecules

Answer 2

H2O, ethanol, glycerol

can pass through membrane, but not very well

Question 3

larger uncharged polar molecules

Answer 3

amino acids, glucose, nucleosides

very, very small amount can pass through membranes

Question 4

ions

Answer 4

cannot pass through membranes

Question 5

membrane transport

Answer 5

simple diffusion, channel-mediated, transport-mediated (active and passive)

Question 6

transporters

Answer 6

are active or passive -

specific for a certain ion

Question 7

energy for active transport

Answer 7

ATP
electrochemical gradients
Light
(help regulate the gradients)

Question 8

passive transport

Answer 8

facilitated diffusion

uses the concentration gradient

Question 9

passive transport of ions

Answer 9

must account for concentration gradient AND membrane potential

Question 10

active transport

Answer 10

must couple to something providing free energy

Question 11

active transport pump types

Answer 11

coupled pump (indirectly uses energy)
ATP-driven pump
Light-driven pump

Question 12

Na+/K+ pump

Answer 12

active transport
“pay it forward” NEED the electrochem gradient to power other processes
ATP-mediated phosphorylation drives conformation changes
P-type transporter

Question 13

P-type transporter

Answer 13

Transient ATP-mediated phosphorylation drives conformation changes

Question 14

transporter types

Answer 14

uniport, symport, antiport

Question 15

coupled transport

Answer 15

symport and antiports - couples two ions across the membrane -usually using the favorable energy of one ion to help the other across

Question 16

uniport

Answer 16

1 molecule transported across

glucose in some places

Question 17

symport

Answer 17

2 molecules transported from the same side

Na+ and glucose

Question 18

antiport

Answer 18

2 molecules transported from opposite sites
Na+/Ca++
Na+/H+

Question 19

Glucose/Na+ symport

Answer 19

Indirectly uses Na/K energy -intestine

Question 20

tight junctions

Answer 20

keeps proteins from interacting and maintains polarity of the epithelial cells

Question 21

Glucose takeup

Answer 21

Glucose actively transported with Na/glucose symport
facilitatively diffuses across cell
glucose passively pumped into extracellular fluid

Question 22

ATP-mediated pumps

Answer 22

P-type, V-type, F-type

Question 23

V-type pump

Answer 23

vesicle pumps