Active Transport (OCR A Level Biology)

Revision Note

Test yourself
Alistair

Author

Alistair

Last updated

Active Transport

  • Active transport is the movement of molecules and ions through a cell membrane from a region of lower concentration to a region of higher concentration using energy from respiration
  • Active transport requires carrier proteins (each carrier protein being specific for a particular type of molecule or ion)
  • Although facilitated diffusion also uses carrier proteins, active transport is different as it requires energy
  • The energy is required to make the carrier protein change shape, allowing it to transfer the molecules or ions across the cell membrane
  • The energy required is provided by ATP (adenosine triphosphate) produced during respiration. The ATP is hydrolysed to release energy

Carrier protein in active transport, downloadable AS & A Level Biology revision notes

A carrier protein changing shape during active transport

  • Active transport is important in:
    • The reabsorption of useful molecules and ions into the blood after filtration into the kidney tubules
    • The absorption of some products of digestion from the digestive tract
    • The loading of sugar from the photosynthesising cells of leaves into the phloem tissue for transport around the plant
    • The loading of inorganic ions from the soil into root hairs

Examiner Tip

Be careful not to get carrier proteins and channel proteins confused when answering questions on active transport. Active transport requires carrier proteins (transmembrane transport proteins that undergo conformational change) not channel proteins.

You've read 0 of your 10 free revision notes

Unlock more, it's free!

Join the 100,000+ Students that ❤️ Save My Exams

the (exam) results speak for themselves:

Did this page help you?

Alistair

Author: Alistair

Expertise: Biology & Environmental Systems and Societies

Alistair graduated from Oxford University with a degree in Biological Sciences. He has taught GCSE/IGCSE Biology, as well as Biology and Environmental Systems & Societies for the International Baccalaureate Diploma Programme. While teaching in Oxford, Alistair completed his MA Education as Head of Department for Environmental Systems & Societies. Alistair has continued to pursue his interests in ecology and environmental science, recently gaining an MSc in Wildlife Biology & Conservation with Edinburgh Napier University.