question_answer 33)

  Respiration is an energy releasing and enzymatic ally controlled catabolic process which involves a step-wise oxidative breakdown of organic substances inside living cells. In this statement about respiration explain the meaning of Step-wise oxidative breakdown Organic substances (used as substrates).

Answer:

                (a) Respiration is a stepwise oxidation of organic molecules in a cell involving main three steps. (i) Glycolysis                                       (ii) Krebs' cycle                                  (iii) Electron transport chain Glucose passes through series of enzymatic ally controlled reactions and is finally converted into (b) Organic substances are the molecules normally found in living systems. They are usually composed of carbon atoms in rings or long chains to which other atoms such as hydrogen, oxygen and nitrogen are attached, e.g., glucose, fatty acids, amino acids etc. These molecules burnt as substrate to produce energy. Respiration of glucose and fatty acids is called floating respiration and respiration of protein and amino acids are called protoplasmic respiration.