8e – Cellular respiration

Question 1

respiration

Answer 1

• a series of chemical reactions that release energy from glucose.
• as some energy is transferred out of the cells, heating the surroundings, respiration is exothermic.

Question 2

Aerobic respiration

Answer 2

• Aerobic respiration occurs in the mitochondria of cells and requires oxygen.
• Glucose + Oxygen –> Carbon dioxide + water + ENERGY (USEFUL PRODUCT)
• Circulatory system ensures that cells have a good supply of oxygen (taken in by lungs) and glucose (taken in by small intestine), and ensures that waste is carried away from cells.

Question 3

Anaerobic respiration

Answer 3

• occurs when oxygen is used up faster than it’s replaced. It occurs in the cytoplasm and does not require oxygen, and produces lactic acid.
• Glucose –> Lactic acid
• This could occur during exercise. (During exercise, the muscles require more energy to work, so the rate of aerobic respiration increases. The cells take in more glucose and oxygen from the blood and the heart beats faster to pump more blood to muscles. You take deeper breathes to increase volume of oxygen diffusing into lungs, and increase volume of CO2 leaving lungs).
• Anaerobic respiration useful as it releases sudden bursts of energy without needing an increased oxygen supply, important for animals that need to sprint fast (E.g. escaping prey)