Question

The end-product of respiration is

• A. Carbon dioxide.
• B. Water.
• C. Both carbon dioxide and water.
• D. None of the above.

Answer 1

The correct option is C Both carbon dioxide and water.

Respiration is a process of production of energy in the form ATP by the oxidation of simple sugar i.e., glucose. Glucose is produced in cells by the breakdown of more complex carbohydrates. This glucose then converted into the 3 carbon compound i.e., pyruvate in the cytoplasm of the cell which then enters into the mitochondria where respiration takes place and is called as cellular respiration. The overall chemical change that occurs in cellular respiration can be represented by a fairly simple chemical equation:
6C${}_6$ H${}_{12}$ O${}_6$ + 6O${}_2$ → 6 CO${}_2$ + 6 H${}_2$O + 36 ATP
That equation says that six molecules of glucose (6C${}_6$ H${}_{12}$ O${}_6$) react with six molecules of oxygen (O${}_2$) to form six molecules of carbon dioxide (CO${}_2$), six molecules of water (H${}_2$O) and 36 molecules of ATP.

Therefore, the correct answer is option C.