7.4 active transport

Question 1

when does cell use energy to transport

Answer 1

against the gradient

Question 2

the type of protein that does this

Answer 2

carrier proteins

Question 3

what does active transport maintain homeostasis

Answer 3

maintain internal conditions of small solutes that differ from concentrations in its environment

Question 4

how does the protein get energy

Answer 4

ATP

• transfers its terminal phosphate group directly to the transport protein, casings it
• to change shape

Question 5

sodium potassium pump

Answer 5

• 3 Na out for every

- 2 K in

Question 6

how does a sodium potassium pump work

Answer 6

1-Na+ binds to pump
2-this stimulates ATP to give it energy
3- Phosphorylation causes protein to change shape and release Na+ outside the cell (using the energy up)
4-K+ binds to it
5-protein returns to old shape and releases K+
6- repeat cycle

Question 7

cell voltage

Answer 7

• cytoplasm is (-) in relation to extracellular fluid

- therefore cations (+) want to come in to the cell and anions (-) want out

Question 8

membrane potential

Answer 8

the voltage across a membrane

-ranges from -50 to -200 millliVolts

Question 9

the elctrochemical gradient

Answer 9

forces acting on an ion in transportation

the chemical force (concentration gradient) +
the electrical force (membrane potential)

Question 10

a transport protein that generates voltage across membrane is a :

Answer 10

electrogenic pump

Question 11

main electrogenic pump in animals

Answer 11

sodium potassium ump

Question 12

main electrogenic pmp in plants fungi bacteria

Answer 12

proton pump

-transports h+ out of the cell

Question 13

cotransport

Answer 13

a specific ATP powered pump drives the active transport of several there solutes