Additional Science Biology

Respiration in cells can take place aerobically or anaerobically. The energy released is used in a variety of ways. The human body needs to react to the increased demand for energy during exercise.

• Chemical reactions inside cells are contolled - enzymes
• During aerobic respiration- uses oxygen - chemical reactions occur that : Use glucose + oxygen and release energy.
• Aerobic respiration take place continuously in both plants and animals
• Most reactions in aerobic respiration take place in - Mitochondria
• Aerobic respiration equation: Glucose + Oxygen - Carbon dioxide + water(+ energy) 
• Energy that is released during respiration - used by organisms. The energy may be used: - build larger molecules - from smaller ones - in animals, to enable muscles to contract - In mammals and birds, to maintain a steady body tempreture in colder surroundings - In plants to build up sugars, nitrates and others into amino acids, then build them into protiens
• During exercise the heart rate increases and the rate and depth of the breathing increases. These changes increase the blood flow - to muscles - increase the supply of sugar+oxygen and increase - rate of removel of carbon dioxide.
• Muscles store glucose as glycogen - can then be coverted back to glucose for use during exercise.

Anaerobic respiration 

• During exersise - if not enough oxygen is reaching the muscles they use anaerobic respiration to get energy 
• Anaerobic respiration is the incomplete breakdown of glucose and produces lactic acid

• As the breakdown od glucose is incomplete, much les energy is released than during aerobic repiration. Anaerobic respiration results in an oxygen debt that has to be repaid in order to oxidise lactic acid to cardon dioxide and water