Respiration: All organisms respire to release energy for living processes.
Aerobic respiration: Uses glucose and oxygen.
Anaerobic respiration: Uses only glucose.
Importance
Part of the Biology (Single Science) curriculum under Bioenergetics.
Oxygen Debt
Definition: Oxygen debt is the amount of oxygen required to remove lactic acid and replenish the body's oxygen reserves post-exercise.
Post-exercise Recovery:
Lactic acid must be removed as it is only tolerated in small amounts by the body.
After exercise, both breathing and heart rate remain elevated to clear lactic acid and restore oxygen reserves.
Role of the Liver
Conversion Process:
Lactic acid is transported to the liver via blood.
In the liver, lactic acid can be:
Oxidized to carbon dioxide and water, or
Converted back to glucose and subsequently glycogen.
Glycogen Restoration:
Glycogen levels in the liver and muscles can be replenished.
Recovery Time
Oxygen Debt Repayment: Depends on the intensity and duration of the exercise.
Normal exercise recovery may take a few hours.
Extended recovery, such as post-marathon, can take several days.
Additional Resources
Further reading and revision available through BBC Bitesize resources, including topics on photosynthesis and sample exam questions related to bioenergetics.