active transport

What is active transport

The movement of molecules or ions across a cell membrane from a region of low concentration to a region of high concentration using energy from ATP

Active transport requires energy. Where does this energy come from

From ATP

Why is active transport described as moving substances “against” the concentration gradient

It moves them from where they are in low concentration to where they are already in high concentration

Which special proteins in the cell membrane carry out active transport

Carrier proteins (pumps)

Name the famous example of active transport in animals

The sodium-potassium pump in nerve cells

Give two examples of substances that plants take in by active transport

Nitrates, mineral ions

Root hair cells are adapted for active transport. Name two adaptations

• large surface area

• Many mitochondria

How is active transport different from diffusion

Diffusion = high - low concentration not using energy

Active transport = low - high energy is needed

How is active transport different from osmosis

Osmosis is the diffusion of water only and active transport moves in different substances against their concentration gradient using energy.

If respiration is inhibited, what happens in active transport

It stops because it has no energy available