Active transport

Active transport

Movement of molecules and ions from an area of higher concentration to an area of lower concentration (against the concentration gradient) using ATP and carrier proteins

Carrier proteins act as pumps to move substances across membranes
Very selective- only certain molecules can bind to the carrier proteins to be pumped

Step 1

Transport is through carrier proteins spanning the cell membrane

Step 2

Molecule binds to a receptor complimentary in shape on the protein

step 3

ATP binds to the carrier protein from the inside of the cell and it is hydrolysed into ADP + Pi

Step 4

This causes the carrier protein to change shape and release the molecule to the other side