12.1) Respiration Most of the processes taking place in cells need energy to make them happen. Examples of energy-consuming processes in living organisms are: The contraction of muscle cells - to create movement of the organism, or peristalsis to move food...
12.2) Aerobic respiration Aerobic respiration: is the term for chemical reactions in cells that use oxygen to break down nutrient molecules to releases energy. The word aerobic means that oxygen is needed for this chemical reaction. The food molecules are...
12.3) Anaerobic respiration Anaerobic respiration: is the term for the chemical reactions in cells that break down nutrient molecules to release energy without using oxygen. The word anaerobic means ‘in the absence of oxygen’. Anaerobic respiration happens in...