Transport Across a Cell Membrane

Question 1

symporter

Answer 1

couples the transport of two molecules to move glucose against its concentration gradient

the molecules move in the same direction

Question 2

fenestrations

Answer 2

small windows in nephrons that allow passage of small molecules across the membrane

Question 3

lowering temperature slows/speeds equilibrium

Answer 3

slows the equilibrium process by decreasing the kinetic energy

Question 4

cholera

Answer 4

turns on the chlorine transporter in the intestine, so water goes out osmotically

Question 5

potassium moves up/down the concentration gradient, up/down the membrane potential

Answer 5

up the concentration gradient, down the membrane potential

it goes toward an area of higher potassium concentration, but because there are anions inside the cell, it goes down the membrane potential

the plateau is around -92 mV (the equilibrium potential)

Question 6

electric gradient and concentration

Answer 6

they can balance each other out, such at a cation can exist in high concentrations inside the cell if there is a negative charge inside

Question 7

apical side

Answer 7

faces the lumen

Question 8

rank the 4 types of cell movement by ATP use

Answer 8

1. (highest) phagocytosis
2. sodium/potassium pump
3. symporter
4. leaky channel

Question 9

down the gradient

Answer 9

from high to low; requires no energy

Question 10

antiporter

Answer 10

molecules go in opposite directions

Question 11

sodium and glucose (symport)

Answer 11

sodium goes into the cell (it wants to go inside the cell) and helps glucose get into the cell

this is an example of symport

Question 12

sodium and calcium in the heart

Answer 12

bring in sodium, pump calcium out (antiporter)

Question 13

leaky channel

Answer 13

Potassium is generally higher inside the cell
Na is generally higher outside of the cell

“Special K in the house, Na I’m outside”

Question 14

primary active transport

Answer 14

use of ATP to push something against its concentration gradient

Question 15

secondary active transport

Answer 15

antiport: we want glucose to leave the cell into the blood stream, so we let Na+ inside and send glucose out (they go in opposite directions)

Question 16

endocytosis/exocytosis

Answer 16

for something to go into a cell (uses a lot of energy) or to exit a cell (also uses a lot of energy)

Question 17

endothelial cells

Answer 17

the cells lining the glomerulus of the afferent arterial in the kidney, which are fenistrated

Question 18

facilitated diffusion

Answer 18

something has to facilitate the movement of polar molecules across the membrane; proteins like a chloride channel

Question 19

diffusion

Answer 19

the process of moving from high to distributed, lower concentrations

Question 20

hypertonic, hypotonic

Answer 20

high and low concentration

Question 21

glomerulus

Answer 21

a loopy structure that accepts blood from the afferent artery, where filtration occurs

Question 22

the Bowman’s capsule

Answer 22

where the filtrate comes out of the glomerulus (Bowman’s space)

Question 23

basement membrane

Answer 23

another barrier between glomerulus and Bowman’s space

Question 24

tubular cells

Answer 24

epithelial cell; podocytes that go into the basement membrane and endothelial cell

Question 25

nerve cell

Answer 25

more positive outside, forming an electropotential gradient

Question 26

sodium-potassium pump

Answer 26

active transport (sodium-potassium ATPase)

sodium is pumped (3 at a time), with ATP, out of the cell and into the blood, leaving low sodium concentration in the cell.

the potassium is pumped back into the cell

Question 27

resting voltage difference in a nerve cell

Answer 27

it is 70mV more positive on the outside than the inside

Question 28

leaky channels

Answer 28

maintains the 70mV difference

Question 29

proximal convoluted tubule

Answer 29

glucose, amino acids being reabsorbed

Question 30

ascending part of loop of Henle

Answer 30

salts: sodium, potassium, chlorine being reabsorbed

Question 31

distal proximal tubule

Answer 31

calcium

Question 32

sodium-potassium-chlorine symporter

Answer 32

**

Question 33

exocytosis

Answer 33

the membrane of the bubble merges with the membrane of the cell. crucial to cell process

Question 34

phagocytosis

Answer 34

a process in which a cell binds to the item it wants to engulf and then engulfs it, often in an attempt to destroy it

1. opsonin receptor
2. scavenger receptor
3. toll-like receptor
4. antibodies