Aerobic & Anaerobic Respiration

chemical reactions inside cells controlled by enzymes. During aerobic respiration chemical reactions occur that:

• use glucose (a sugar) & oxygen
• release energy

Aerobic respiration takes place continuously in plants & animals. Most of the reactions involved in aerobic respirationtake make in the mitochondria in cytoplasm of cells

Energy that is released during respiration may be used:

• to build larger molecules from smaller ones
• to allow muscles to contract (in animals)
• to maintain a steady body temperature in colder surroundings
• to build up amino acids from sugars, nitrates & other nurtrients, which then combine to from proteins 

During exercise a number of changes take place in your body:

• your heart rate increases 
• the rate & depth of your breathing increases 
• the arteries supplying your muscles dilate
• bloodflow to your muscles increases
• the supply of oxygen & sugar & removal of carbon dioxide is increased 

Muscles store glucose as glycogen, which can then be converted back to glucose for use during exercise 

If there isn't enough oxygen reaching your muscles, they use anaerobic respiration to obtain energy

Anaerobic respiration releases energy without oxygen. It is the incomplete breakdown of glucose and produces lactic acid

If muscles carry out vigorous activity for a long time they become fatigued - they stop contracting efficiently & hurt

Muscle fatigue is caused by the build up of lactic acid in the muscles. Blood flowing through the muscles will remove the lactic acid