all living cells need to respire to produce energy. most resiration needs oxygen, this is called aerobic respiration. respration that does not need oxygen is called anaerobic respiration. one example of aerobic respiration is ths equation glucose+oxygen-carbon dioxide + water glucose and oxygen ae the reactants and carbon dioxide and water are the products. glucose is made by the digestion of carbohydrates. it is absorbed in to the blood in the small intestines and is dissolved in the plasma. oxygen is absorbed from the air by the lungs which are part of the respiratory system.
tissue fluid comes out of capillaries around the body. tissue fluid contains oxygen and glucose. cells take what they need from the tissue fluid to respire and they put carbon dioxide back into the tissue fluid. the tissue fluid sos back into the capillaries and the carbon dioxide dissolves back into the blood plasm.