Diffusion and Temperature-How Temperature Controls Movement

Temperature affects the rate of diffusion in biological processes because it affects the kinetic energy of molecules. Molecules with more kinetic energy move faster, so they diffuse faster.

For example, if you have two cups of water, one at room temperature and the other at a higher temperature, the molecules in the hotter cup of water will have more kinetic energy. This means that the molecules will move faster and diffuse more quickly.

Examples of how Temperature Affects Diffusion Rate

Temperature effects diffusion in number of biological processes as:

1.    Gas exchange in the lungs

Oxygen diffuses from the air in the lungs to the blood in the capillaries. The higher the temperature of the air, the faster the oxygen molecules will move and the more oxygen will diffuse into the blood. 

2.    Nutrient absorption in digestive tract

Nutrients diffuse from the digestive tract into the bloodstream. The higher the temperature of the food, the faster the nutrient molecules nutrients will diffuse into the bloodstream.

3.    Hormone transport

If the temperature of the body is high, hormones will diffuse quickly into the bloodstream. This is why some hormones, such as adrenaline, are released when the body is under stress, as this causes the body temperature to rise.

4.    Enzyme activity

Enzymes are sensitive to temperature, and their activity increases with temperature up to a certain point. 

If the temperature gets too high, the enzymes can be denatured and inactivated. This is why it is important to maintain a certain range of body temperature for optimal enzyme activity.

5.    Membrane fluidity

The cell membrane is a phospholipid bilayer that is essential for many cellular processes. The fluidity of the cell membrane is affected by temperature. At lower temperatures, the phospholipid molecules become more rigid, making the cell membrane less fluid. 

At higher temperatures, the phospholipid molecules become more fluid, making the cell membrane more fluid. This can affect the rate of diffusion of molecules across the cell membrane.