- The cells in our body need energy to: Contract muscles, so we can move; make protein molecules by linking together amino acids into long chains; repair damaged tissues through cell division so we can grow; carry on active transport; transmit nerve impulses, so we can transfer information quickly; to produce heat inside the body, to keep the body temperature constant if the environment is cold.
3. When we run in a race, for example, we need a lot of oxygen in order to release energy to contract our muscles. We keep on running, maybe faster, and we need every time more and more energy. Our heart starts to beat faster because we need energy to reach our blood more quickly since we are constantly losing it. But eventually we can’t breath more quickly than we have been doing. There is when we produce “extra energy” by anaerobic respiration. Glucose is broken down without combinating it with oxygen. This action releases lactic acid and energy. “Oxygen Debt” is this action. When we “borrow” some extra energy without “paying” for it with oxygen. As a consequence of this we have a lot of lactic acid left in our muscles and blood which can be broken down by combinating by aerobic respiration.