Red Blood Cells
Biology: AQA GCSE Higher, topic 2.3.14
Red Blood Cells
Red blood cells transport oxygen from the lungs to all body cells. They are adapted to do this function because of their features:
Biconcave shape
- Red blood cells have dents on each side.
- We call this a biconcave shape.
- This biconcave shape creates a large surface area and allows for the rapid diffusion of oxygen.
Haemoglobin
- Haemoglobin is found in red blood cells. Haemoglobin binds with oxygen in the lungs.
- Haemoglobin carries oxygen which will then be released to the body cells to be used for respiration.
No nucleus
- Red blood cells do not have a nucleus. This frees up more room for haemoglobin.
- This maximises the amount of oxygen that they can carry.
Small size
- Red blood cells are small so that they can pass through tiny capillaries.
Test yourself on Red Blood Cells
What would happen if red blood cells had a nucleus?
Why are red blood cells small in size?
Why does the biconcave shape of a red blood cell increase the rate of oxygen diffusion?
Why do whales have about twice as much haemoglobin in their blood as humans?
What would happen to the surface area available for oxygen diffusion if a red blood cell's shape changed from biconcave to spherical?