1.3 Active transport Flashcards
(18 cards)
Define active transport.
The movement of molecules or ions
across a membrane against a
concentration gradient, using energy from
the hydrolysis of ATP made by the cell in
respiration.
Give examples of active transport.
Muscle contraction, mineral uptake into the plant root, nerve impulses being transmitted and reabsorption of glucose into the kidney.
What does active transport require?
ATP.
Where does active transport occur?
Through the intrinsic
proteins spanning the membrane.
What happens in active transport?
Ions and molecules are moved from a
lower to a higher concentration gradient
against the concentration gradient.
How does the process of active transport happen?
Active transport is the pumping of
substances across a membrane by a
protein pump molecule.
What are protein pumps?
Intrinsic carrier
proteins.
How do protein pumps work?
The protein binds a molecule of the substance to be transported on one side of the membrane, changes shape, and releases it on the other side.
Protein pumps are highly specific. What does this mean?
There is a different protein pump for each molecule to be transported.
What do protein pumps use to change shape?
Energy/ATP.
What is a feature of a protein pump?
They can only work in one direction.
Is active transport faster than diffusion?
Yes.
How do protein pumps use energy?
To change shape and pump the molecule.
What is step 1 in the protein pump process?
The molecule or ion combines with a specific carrier protein.
What is step 2 in the protein pump process?
ATP transfers a phosphate group to the carrier protein on the inside of the membrane.
What is step 3 in the protein pump process?
The transport protein changes shape and carries the molecule or ion across the membrane.
What is step 4 in the protein pump process?
The molecule or ion is released into the cytoplasm.
What is step 5 in the protein pump process?
The phosphate is released from the carrier molecule back to the cytoplasm and recombines with ADP to form ATP.
