Concept 7.4: Active transport uses energy to move solutes against their gradients

Question 1

to pump a solute across a membrane against its gradient requires work; the cell must expend energy. Therefore, this type of membrane traffic is called

Answer 1

active transport

Question 2

The transport proteins that move solutes against their concentration gradients are all

Answer 2

carrier proteins

Question 3

exchanges Na+ for K+ across the plasma membrane of animal cells

Answer 3

sodium-potassium pump

Question 4

is electrical potential energy

Answer 4

Voltage

Question 5

The cytoplasmic side of the membrane is

Answer 5

negative in charge relative to the extracellular side because of an unequal distribution of anions and cations on the two sides

Question 6

the difference in electrical charge (voltage) across a cell’s plasma membrane due to the differential distribution of ions. membrane potential affects the activity of excitable cells and the transmembrane movement of all charged substances is called

Answer 6

membrane potential

Question 7

combination of forces acting on an ion is called the

Answer 7

electrochemical gradient

Question 8

A transport protein that generates voltage across a membrane is called an

Answer 8

electrogenic pump

Question 9

main electrogenic pump of plants, fungi, and bacteria is a

Answer 9

proton pump

Question 10

One important use of proton gradients in the cell is for ATP synthesis during

Answer 10

cellular respiration,

Question 11

transport protein (a cotransporter) can couple the “downhill” diffusion of the solute to the “uphill” transport of a second substance against its own concentration gradient

Answer 11

cotransport