Question

nutrition and respiration require energy which is obtained from food. how? and why?

Answer 1

The food that we eat is digested and absorbed by our digestive system . This whole process of digestion requires the expenditure of energy. The food that is broken down into simpler compounds by the digestive system is absorbed and transported to tissues where cellular respiration takes place . During respiration oxygen is taken in. The digested food in the presence of oxygen is broken down to release energy .This energy is again utilised for various life processes like nutrition, respiration etc.