Active transport (AQA GCSE Biology)

Revision Note

Lára Marie McIvor

Written by: Lára Marie McIvor

Reviewed by: Lucy Kirkham

Loading video: 3.1.7 AQA GCSE Active Transport

Did this video help you?

Principles of Active Transport

  • Diffusion and osmosis rely upon the passive transport of substances down concentration gradients, relying on the random movement of particles

  • However, cells also need to be able to transport substances across the cell membrane against a concentration gradient. This requires energy released by respiration

    • The energy from respiration is used by protein transport molecules embedded in the cell membrane to move substances into or out of the cell

  • Active transport moves substances from a more dilute solution to a more concentrated solution

active-transport-across-the-cell-membrane-igcse-and-gcse-biology-revision-notes

Active transport across the cell membrane involves protein carrier molecules embedded in the cell membrane

Active Transport: Examples

Plants

  • Root hair cells lining the surface of plant roots need to move minerals such as magnesium ions from a region of lower concentration (the very dilute solution of minerals in the soil surrounding the roots) to a region of higher concentration (inside the cytoplasm of the cell)

  • Mineral ions are needed by plants to function healthily

    • Magnesium ions are needed to make chlorophyll

    • Nitrate ions are needed to make amino acids and therefore for protein synthesis (and subsequently growth)

Animals

  • Food molecules (such as the sugar glucose) can be absorbed across the wall of the small intestine by diffusion, but this is dependent on a concentration gradient existing between the lumen of the intestine and the bloodstream

  • Active transport allows sugar such as glucose to be transported into the bloodstream from the lumen of the small intestine (the gut) when the concentration of sugar molecules in the blood is higher

    • Sugar molecules are used in respiration to release energy for cells to function

Last updated:

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?

Lára Marie McIvor

Author: Lára Marie McIvor

Expertise: Biology Lead

Lára graduated from Oxford University in Biological Sciences and has now been a science tutor working in the UK for several years. Lára has a particular interest in the area of infectious disease and epidemiology, and enjoys creating original educational materials that develop confidence and facilitate learning.

Lucy Kirkham

Author: Lucy Kirkham

Expertise: Head of STEM

Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels.Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the East Midlands, where her role was to support and coach teachers to improve Maths teaching for all.