active, bulk, and cotransport

Question 1

passive transport

Answer 1

No Energy
Diffusion, Osmosis, Facilitated Diffusion
Move down concentration gradient From HIGH to LOW

Question 2

facilitated diffusion

Answer 2

Speeds up the transport, but does not change the direction
passive transport

Question 3

active transport

Answer 3

moves substances AGAINST their concentration gradient
requires energy

Question 4

what form is the energy in with active transport

Answer 4

ATP usually

Question 5

how does active transport work

Answer 5

Transfers a terminal phosphate group to the transport protein
induce change in shape
translocates solute across

Question 6

what proteins do active transport

Answer 6

carrier

Question 7

active transport allows cells to maintain

Answer 7

concentration gradients that differ from their surroundings

Question 8

2 common examples of active transport

Answer 8

sodium-potassium pump,
proton pump

Question 9

6 stages of sodium potassium pump

Answer 9

1. cytoplasmic Na binds to sodium-potassium pump
2. Na binding stimulates phosphorylation by ATP
3. phosphorylation causes the protein to change its shape, Na is expelled to the outside
4. Potassium binds on the extracellular side and triggers release of the phosphate group
5. loss of the phosphate restores the protein’s original shape
6. potassium is released and the cycle repeats

Question 10

membrane potential definition

Answer 10

voltage difference across a membrane
Electrical potential energy, acts like a battery

Question 11

how is membrane potential created

Answer 11

by differences in the distribution of positive and negative ions

Question 12

what is membrane potential maintained by

Answer 12

ion pumps

Question 13

cell (inside and outside) voltages

Answer 13

Inside cell: NEGATIVE
Outside cell: POSITIVE
Membrane potential ranges from -50 to -200 millivolts (mV)

Question 14

what does membrane potential affect

Answer 14

the traffic of all charged substances

Question 15

Because the inside is NEGATIVE, the cell membrane potential favors

Answer 15

the passive transport of cations (+) INTO the cell and anions (-) OUT of the cell

Question 16

electrochemical gradient

Answer 16

Force acting on an ion that drives the diffusion of ions across a membrane from chemical and electrical force

Question 17

chemical force

Answer 17

the ion’s concentration gradient

Question 18

electrical force

Answer 18

the effect of the membrane potential on the ion’s movement

Question 19

In cases where electrical forces due to membrane potential oppose simple diffusion of an ion down its concentration gradient, what might be necessary?

Answer 19

active transport

Question 20

electrogenic pump

Answer 20

transport protein that generates voltage across a membrane

Question 21

sodium-potassium pump

Answer 21

major electrogenic pump of animal cells
With each “crank” of the pump, there is a net transfer of 1 + charge from cytoplasm to the extracellular fluid

Question 22

sodium-potassium pump stores energy as

Answer 22

voltage

Question 23

sodium-potassium pump ion exchange

Answer 23

Pumps 3 Na+ ions OUT of the cell for every 2 K+ ions INTO the cell

Question 24

proton pump

Answer 24

The main electrogenic pump of plants, fungi, and bacteria

Question 25

proton pump ion exchange

Answer 25

Actively transports H+ protons OUT of the cell

Question 26

cotransport

Answer 26

active transport of a solute indirectly drives transport of another solute A substance that has been pumped across a membrane can do work as it moves back across by diffusion Plants commonly use the gradient of hydrogen ions generated by proton pumps to drive active transport of nutrients into the cell

Question 27

bulk transport requires

Answer 27

energy

Question 28

how do Large molecules, such as polysaccharides and proteins, cross the membrane in bulk?

Answer 28

vesicles

Question 29

what do Small molecules and water enter or leave the cell through

Answer 29

lipid bilayer or transport proteins

Question 30

exocytosis

Answer 30

transport vesicles migrate to the membrane, fuse with it, and release their contents

Question 31

many secretory cells use _ to export their products

Answer 31

exocytosis

Question 32

endocytosis

Answer 32

the cell takes in macromolecules by forming vesicles from the plasma membrane

Question 33

relationship between endocytosis and exocytosis

Answer 33

Endocytosis is a reversal of exocytosis, involving different proteins

Question 34

3 types of endocytosis

Answer 34

Phagocytosis (“cellular eating”) Pinocytosis (“cellular drinking”) Receptor-mediated endocytosis

Question 35

phagocytosis

Answer 35

cell engulfs a particle/food in a vacuole The vacuole fuses with a lysosome to digest the particle

Question 36

pinocytosis

Answer 36

molecules are taken up when extracellular fluid is “gulped” into tiny vesicles

Question 37

receptor-mediated endocytosis

Answer 37

binding of ligands to receptors triggers vesicle formation

Question 38

ligand

Answer 38

any molecule that binds specifically to a receptor site of another molecule