ACTIVE TRANSPORT Flashcards
What is active transport
the movement of molecules or ions into or out of a cell from a reguin oof lower concentration to a region of higher concentration using ATP and carrier proteins
What is active transport used for (2 points)
1) directly move molecules
2) individually move molecules using a concentration gradient (co-transport)
How does active transport differ from passive transport (3 points)
1) metabolic energy from ATP is needed
2) substances are moved against a concentration gradient
3) process is very selective with only specific substances being transported
Describe the process of active transport with a single molecule (4 points)
1) the molecule/ion binds to the receptor site of the carrier protein in the plamsa membrane
2) which causes, on the inside of the cell, ATP to bind to the protein where it is hydrolysed into ADP+Pi, so the protein molecule change shape
3) the molecule/ion is released to the other side of the membrane
4) the phosphate molecule is released from the protein which causes the protein to revert back to its original shape and then recombines with ADP to form ATP during respiration
What form is the metabolic energy that active transport requires
ATP
What happens at the sodium-potassium pump
sodium ions are actively transported out of the cell whilst potassium ions are actively transported into the cell
What process is the sodium-potassium pump vital for
nerve impulse
What are the factors that affect the rate of active transport (3 points)
1) speed of individual carrier proteins
2) number of carrier proteins present
3) rate of respiration
How does the speed of carrier proteins affect the rate of active transport
faster they work = faster rate of active transport
How does the number of carrier proteins affect the rate of active transport
more proteins = faster rate of active transport
How does the rate of respiration affect the rate of active transport
faster respiration = moer ATP available = faster rate of active transport
