2.19 Active transport

Active transport

the movement of molecules and ions through a cell membrane from a region of lower concentration to a region of higher concentration

• requires energy in the form of ATP (from respiration )to move substances against their concentration gradient

• active process

Active transport needs…

carrier proteins (specific to particular molecule/ion)

Why is energy needed?

• to change shape

• provided by ATP (in respiration)

• ATP is hydrolysed to release energy

Hydrolysed

broken down by adding water

Examples:

• Reabsorption of useful molecules and ions into the blood after filtration into the kidney tubules

• Loading inorganic ions from the soil into root hair cells