Active transport

Active Transport

• Uses ATP (energy)

• Actively moves molecules to where they’re needed

• Movement from an area of low concentration to an area of high concentration

Types of Active transport - Proton or Ion Pump

Transport proteins that require ATP/energy to do work. The protein changes shape to move molecules - this requires energy.

Co-transport

When two molecules are transported across the cell membrane together.

E.g this happens on the epithelial cells of the small intestine

Types of Active transport Cytosis(two types)

I. Endocytosis=Taking bulky material into the cell

The cell membrane infolds around a particle

ii. Exocytosis= forcing bulky material out of the cell

An change in shape > requires ATP/energy

What could be a reason for why cells need to be so small? - Surface Area to Volume Ratio ( SA:V)

Materials can move in and out of the cell by diffusion and active transport.

The larger the cell, the less efficient it’s ability to perform cellular transport will be. Small cells have a higher SA, lower V makes them more efficient at cell transport.

Some cells are specialized to have an increased SA:V, by having folds. This aids in the movement of materials.