What are the chemical reactions in cells controlled by?
Enzymes
During aerobic respiration what do chemical reactions use?
Glucose and oxygen
During aerobic respiration what do chemical reactions release?
Energy
Aerobic respiration takes place…
Continuously in plants and animals
Where do most of the reactions in aerobic respiration take place?
Inside mitochondria
What is the equation for aerobic respiration?
Glucose + Oxygen ===> Carbon Dioxide + Water (+ energy)
Energy released during respiration may be used to build…
Larger molecules from smaller ones
In animals, energy released from respiration may be used to enable…
Muscles to contract
In mammals and birds, energy released from respiration may be used to maintain…
A steady body temperature in colder surroundings
In plants, energy released from respiration may be used to build up…
Sugars, nitrates and other nutrients into amino acids which are then built up into proteins
What changes occur during exercise?
Heart rate increases and the rate and depth of breathing increases
What do the changes in your body during exercise help to do?
Increase the blood flow to the muscles, increase the supply of sugar and oxygen and increase the removal of carbon dioxide
What can muscles store glucose as?
Glycogen
What happens to glycogen during exercise?
It is converted back into glucose
When is anaerobic respiration used?
During exercise if there is an insufficient amount of oxygen reaching the muscles
What is anaerobic respiration?
The incomplete breakdown of glucose and the production of lactic acid
Why is there less energy released by anaerobic respiration?
Because the breakdown of glucose is incomplete
What does anaerobic respiration result in?
Oxygen debt that needs to be repaid in order to oxidise the lactic acid to carbon dioxide and oxygen
What happens if muscles are subjected to long periods of vigorous activity?
They become fatigued, ie they stop contracting efficiently
What is a cause of muscle fatigue?
The build up of lactic acid in the muscles
What removes lactic acid from the muscles?
Blood flowing through the muscles
