Aerobic and Anaerobic Respiration
Respiration is the process of transferring energy from the breakdown of glucose, occurring in every cell. It is an exothermic process, meaning it releases energy to the environment.
Aerobic Respiration
Aerobic respiration is the primary form of respiration in plants and animals, occurring continuously in the mitochondria of cells.
Definition: Aerobic respiration is the process of breaking down glucose using oxygen to release energy.
The equation for aerobic respiration is:
Highlight: Glucose + Oxygen → Carbon dioxide + Water + (Energy released)
Reasons for respiration include:
- Metabolism: Energy is needed for chemical reactions, including synthesis and breakdown of molecules.
- Muscle contraction: Not just in skeletal muscles, but also in the digestive system, diaphragm, and heart.
- Maintaining body temperature: Mammals and birds require energy to keep a constant body temperature.
- Transporting mineral ions: Plants use energy to move minerals from soil into root hair cells.
Responses to Exercise
During exercise, the body responds in several ways:
- Breathing rate increases, and lungs breathe more deeply to enhance oxygen intake and carbon dioxide exhalation.
- Glycogen stored in muscles and liver is converted back to glucose for muscle respiration.
- Heart rate increases, and arteries dilate to improve blood flow to muscles, supplying more oxygen and glucose while removing carbon dioxide.
Example: Physically fit individuals often have increased lung capacity and lower resting breathing rates due to regular exercise and training.
Anaerobic Respiration
Definition: Anaerobic respiration is the incomplete breakdown of glucose without oxygen, producing lactic acid.
Anaerobic respiration occurs during emergencies, such as intense exercise, allowing muscles to function for longer periods.
Highlight: In muscle cells: Glucose → Lactic acid
Anaerobic respiration in plants and yeast (fermentation) produces different products:
Example: In plants and yeast: Glucose → Ethanol + Carbon dioxide
Comparing aerobic and anaerobic respiration:
- Aerobic: Uses glucose and oxygen, produces carbon dioxide and water, releases more energy.
- Anaerobic: Uses only glucose, produces lactic acid, releases less energy.
Muscle Fatigue and Oxygen Debt
Muscle fatigue occurs when muscles contract less efficiently due to fatigue, often caused by lactic acid buildup in muscle cells.
Vocabulary: Oxygen debt refers to the amount of oxygen required to break down accumulated lactic acid after intense exercise.
