4.4-ACTIVE TRANSPORT Flashcards Preview

B4- TRANSPORT ACROSS CELL MEMBRANES > 4.4-ACTIVE TRANSPORT > Flashcards

Flashcards in 4.4-ACTIVE TRANSPORT Deck (19)
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1

What is active transport?

movement of molecules/ions into or out of cell from region of lower concentration to region of higher concentration using ATP + carrier proteins

2

What is ATP used to do in active transport? (2)

directly move molecules

individually move molecules using concentration gradient which has already been set up by (direct) active transport
known as co-transport

3

How does active transport differ from passive transport? (4)

metabolic energy in form of ATP needed

substances moved against concentration gradient

carrier protein molecules which acts as "pumps" involved

process very selective, with specific substances being transported

4

Process of direct active transport of single molecule/ion #1

carrier proteins span plasma membrane + bind to molecule/ion to be transported onto other side

5

Process of directive active transport #2

molecule/ion binds to receptor sites on carrier protein

6

Process of directive active transport #3

on inside of cell/organelle, ATP binds to protein, causing it to split into ADP + a phospholipid molecule

7

What happens when the ATP molecule splits into ADP + a phospholipid molecule?

protein molecule changes shape + opens to opposite side of membrane

8

Process of directive active transport #4

molecule/ion released to other side of membrane

9

Process of directive active transport #5

phosphate molecule released from protein which causes protein to revert to its original shape, ready for process to be repeated
phosphate molecules then recombine with ADP to form ATP during respiration

10

Similarity between facilitated diffusion and active transport?

both use carrier proteins

11

Difference between facilitated diffusion and active transport?

facilitated diffusion occurs down a concentration gradient, while active transport occurs against concentration gradient

12

As facilitated diffusion occurs down a concentration gradient, what does it not require but active transport does?

metabolic energy

13

What is metabolic energy provided in the form of?

ATP

14

What can sometime happen with the number of molecules/ions during active transport?

sometimes more than one molecule/ion may be moved in same direction at same time by active transport

15

What can ocassionaly happen with molecules/ions moving in/out of cell/organelle?

molecule/ion moved into cell/organelle at same time as different one being removed from it

16

What is an e.g. of when one molecule/ion enters cell/organelle while other leaves?

sodium-potassium pump

17

Which ion is actively removed from cell/organelle in the sodium-potassium pump?

sodium ions actively removed from cell/organelle

18

Which ions is actively taken from the surroundings in the sodium-potassium pump?

potassium ions actively taken in from surroundings

19

What else uses a similar process to the sodium-potassium pump?

creation of a nerve impulse