Active Transport

Question 1

What is active transport?

Answer 1

-energy requiring process which ions and molecules are moved across membrane against a conc gradient

Question 2

Features of active transport:

Answer 2

-ions and molecules moved from a lower to a higher conc against a conc gradient
-process requires ATP
-process occurs intrinsic carrier proteins spanning the membrane
-rate is limited by number and availability of carrier proteins

Question 3

Processes that require active transport?

Answer 3

-muscle contraction
-nerve impulse transmission
-reabsorption of glucose in kidney and mineral uptake into plant root hairs

Question 4

How uptake of a single ion or molecule happens:

Answer 4

-molecule or ion combines with a specific carrier protein on outside of membrane
-ATP transfers phosphate group to carrier protein on inside of membrane
-carrier protein changes shape and carries molecule or ion across membrane to inside of cell
-molecule or ion released to cytoplasm
-phosphate ion released carrier molecule back to cytoplasm and recombines with ADP to form ATP
-carrier protein returns to original shape