The respiratory systemRespirationIt is a chemical reaction that occurs in all living cells. It is the method by which energy is released from glucose, for our cells to use to keep us functioning. Breathing is not the same as breathing, it is properly called ventilation. Aerobic respiration In cells, glucose and oxygen bind together to produce carbon dioxide and water, which is called aerobic respiration. Oxygen from the air is required for its functioning.Glucose + oxygen -> carbon dioxide+ water (+energy) (energy is released in the reaction)Anaerobic respirationIt is a type of respiration and does not use oxygen. Anaerobic respiration is used, if there is not enough oxygen for aerobic respiration.Glucose -> lactic acid (+ energy released)How glucose and oxygen get to the cells and how to remove carbon dioxideGlucose from food to the cellThe glucose is a type of carbon dioxide; we get it through digestion of the food we eat. Breaks food down into small molecules. Then it can be absorbed through the wall of the small intestine into the bloodstream. Glucose is transported throughout the body dispersed in blood plasma, the pale yellow liquid part of the blood. From the capillaries, the dispersed glucose can diffuse into the body's cells. Subsequently the cell can be used in respiration. Oxygen from air to cells When we take in oxygen, it enters the small air sac called alveoli in the lungs. Then the oxygen diffuses from there into the bloodstream. Oxygen is not contained in plasma, but is transported by red blood cells. It contains red substances called hemoglobin. It combines with oxygen and delivers it to the body through the blood, then lets it go when needed. Like glucose, oxygen can diffuse into the center of the paper, from the blood into the alveoli. It needs a concentration gradient. Therefore the oxygen pressure in the alveoli must be maintained at a higher level than that of the blood and the CO2 pressure in the alveoli must be lower than that of the blood. We do this by breathing, bringing fresh air with lots of oxygen and less CO2 into the lungs and alveoli. The respiratory system is linked to energy metabolism as it allows the intake of gaseous nutrients such as oxygen. We also need oxygen to burn nutrient molecules. The respiratory system is responsible for providing the oxygen needed to burn nutrients for energy and also eliminating metabolic wastes. Additionally, the respiratory system continuously refreshes oxygen to the lungs and disposes of waste products such as carbon dioxide and water through the process of breathing. Energy released by food in the process of breathing.