Aerobic respiration uses oxygen :
glucose+oxygen -----> carbon dioxide+water (+energy)
- Aerobic repiration happens all of the time in the cells of animals and plants
- Most of these reactions take place inside mitochondria ( found in the cytoplasm of a cell)
- These reactions are controlled by enzymes
- Energy is released during respiration is used by the organism in a number of ways
- Plants can make amino acids from sugars, nitrates and other nutrients which can then be built up into larger molecules such as proteins
- Energy can also be used up by animals enabling their muscles to contract so they can move easily
- Mammals and birds also have to keep their temperature steady which the energy from respirations helps with when the animals surroundings are colder than they are
During exercise the muscles respire more than they do at rest meaning that oxygen and glucose must be delivered to them more quickly whilst waste CO2 has to be removed just as effectively.
This can be done by:
- Increasing the heart rate so that more blood flows around the body then this new rate and depth of breathing will increase gaseous exchange ( transfer of oxygen into our blood as carbon dioxide goes out) in the lungs
- Also the muscles store glycogen which converts back to glucose again during exercise
Remember ~~~ Respiration releases energy
~~~ Breathing moves air into and out of our lungs
Anaerobic respiration, muscle fatigue, fitness
Anaerobic respiration involves the incomplete breakdown of glucose and happens when not enough oxygen reaches the muscles to provide energy during exercise.
Glucose -------> lactic acid ( + little energy)
Muscles become fatigued easily during exercise so they stop contracting efficiently. The cause of this is the build up of lactic acid from usiing anaerobic respiration. This lactic acid is removed by more blood flowing through the muscles.
Fit people carry out physical activities better than those who don't exercise as their pulse rate will return back to normal quicker than that of an unfit person. Healthy people are free from disease and infection this in NOT the same as fit.
Anaerobic respiration produces an oxygen debt. This is the amount of oxygen needed to oxidise lactic acid to carbon dioxide and water. The existence of an oxygen debt explains why we continue to breathe deeply and quickly for a while after exercise.