Active Transport

Question 1

what molecules are often transported in organisms via active transport?

Answer 1

ions

Question 2

what is the definition of active transport?

Answer 2

the movement of substances against their concentration gradient (from low to high) across a cell membrane, using ATP and carrier proteins

Question 3

how is the ATP necessary produced?

Answer 3

during aerobic respiration in the mitochondria

Question 4

how are substances transported using carrier proteins?

Answer 4

carrier proteins of specific shape are required to transport a substance of complimentary shape against the concentration gradient

Question 5

why is active transport ATP dependent?

Answer 5

the carrier protein changes shape, which is ATP dependent, as it transports substances in one direction

Question 6

what is an example of active transport?

Answer 6

root hair cells use active transport to absorb minerals from the soil

Question 7

what is cytosis?

Answer 7

mass movement of substances (energy dependent

Question 8

what is ATP?

Answer 8

energy currency

Question 9

how can substances enter and leave cells?

Answer 9

through cytosis

Question 10

how is cytosis possible?

Answer 10

due to the fluid nature of the cell surface membrane

Question 11

what does cytosis require?

Answer 11

energy

Question 12

why does cytosis require energy?

Answer 12

as it involves breaking open the bilayer and then reforming it

Question 13

what are the two types of cytosis?

Answer 13

endocytosis (in)
exocytosis (out)

Question 14

what happens to the membrane always after cytosis?

Answer 14

it always reforms, due to the fluid nature of phospholipids IMPORTANT

Question 15

what is endocytosis?

Answer 15

when substances are moved into a cell

Question 16

what is an example of endocytosis?

Answer 16

WBC engulfing invading pathogens then digest them using enzymes in the lysosome

Question 17

what are the steps of endocytosis?

Answer 17

• the cell surface membrane infolds (invaginates) round substances outside the cell to form a vesicle
  -the vesicle then enter the cell and the membrane reforms
  -ATP provides the energy to form vesicles and move them using motor proteins along the cytoskeleton microtubules

Question 18

what are the two types of endocytosis?

Answer 18

phagocytosis
pinocytosis

Question 19

what is phagocytosis?

Answer 19

-cell eating
vesicle traps solids (eg bacteria) or food substances to be taken into cells

Question 20

what is pinocytosis?

Answer 20

-cell drinking
vesicle traps liquid to be taken into cells

Question 21

how to remember the difference between the two endocytosis’?

Answer 21

pinocytosis
pino grigio —> alcoholic drink

Question 22

what is exocytosis?

Answer 22

when solid or liquid materials are move out of cells, when vesicles fuse with the cell membrane

Question 23

what is an example of exocytosis?

Answer 23

-insulin
it’s made in such large quantities, it must be released into the bloodstream by exocytosis
-cell wall materials are exocytosed in plat cells

Question 24

what are the steps of exocytosis?

Answer 24

-vesicles contain isolated substances
-vesicles move towards the cell surface membrane and fuses with it, enabling the contents of the vesicle to be expelled from the cell
-the membrane then reforms due to the fluid nature of the phospholipid