Regulation Of Membrane Transport

Question 1

T/F plasma membrane is always a barrier to diffusion

Answer 1

T

Question 2

Osmosis

Answer 2

Area of low solute conc. To high solute conc. (High water to low water)

Question 3

Cell volume in hypotonic solutions

Answer 3

Cell volume inc.

net water movement into cells

Question 4

Cell volume in hypertonic solutions

Answer 4

Volume dec.

net water movement is out of cells

Question 5

Other terms for passive transport

Answer 5

Catalyze transport

Facilitated diffusion

Question 6

Primary active transport

Answer 6

. Energy derived from ATP hydrolysis

. moves molecules directly across membrane against electrochemical gradient

Question 7

Na-K-ATPase

Answer 7

Pumps 3 NA ions out of cell and 2 K cells into cell both against gradient
. Uses ATP

Question 8

Secondary active transport

Answer 8

. Ion gradients result from primary active transport drives the transport of other solutes
. Transport of one solute coupled and dependent on another solute (cotransport)
. Transport proteins don’t have ATP activity
. Depend indirectly on ATP hydrolysis bc primary active transport creates gradients used

Question 9

Uniporters

Answer 9

. Transport 1 molecule by passive transport

Question 10

Symport

Answer 10

. Both substrates transported in same direction
. Neither substrate can be transported unless other substrate is also transported
. 1 of the substrates is transported against it’s gradient and the other is w/ its gradient

Question 11

Antiport

Answer 11

. 1 transported into cell and 1 out of cell
. Neither can be transported w/o the other
. 1 is transported along gradient and one against gradient

Question 12

Insulin-insensitive glucose transport

Answer 12

. Glucose transport in most cells

. Glucose uniporters present on cells and will transport glucose into cell when it’s around

Question 13

Insulin-sensitive glucose transport

Answer 13

. Glucose transport into skeletal muscle and adipocytes requires insulin
. Uniporters not present on surface of cells but inside waiting for insulin signal to move to surface

Question 14

Steps for insulin sensitive glucose transport

Answer 14

. Blood glucose inc. so insulin is released
. Insulin signals skeletal muscle and adipocytes cells to move glucose uniporters to cell surface
. Starts transporting glucose
. After a time the process reverses and uniporters move back inside cell by going to intracellular storage pool and vesicles form

Question 15

Locations where glucose is higher inside cells than outside cells so glucose is actively transported

Answer 15

. Choroid plexus
. Prox. Convoluted tubule of kidney
. Epithelial cell brush border in small intestine

Question 16

When glucose is transported against gradient into cells what transporter is used?

Answer 16

Glucose-Na symporter

Question 17

Transporters on epithelial cells

Answer 17

. Na-glucose sympoers on one side and uniporters for glucose on other side to more glucose from cell into blood