Factors affecting respiration

               Respiration is the process of breaking complex food materials into inorganic compounds with the release of energy. Several factors affect the rate of respiration.

A) External factor :

1. Temperature  The optimum temperature for respiration is 20-30 ⁰C. The rate of respiration doubles for energy rises to 10 ⁰C. There isan initial increase, which soon decreases due to the denaturation of the enzyme. Below the 0⁰C, the rate of respiration decreases.

2. Oxygen: The presence of oxygen is the first and most essential condition for respiration. If the concentration of oxygen goes below 5%, the respiration process falls rapidly.

3. Light: The effect of light is indirect in the rate of respiration. In bright light, respiration is greater than in low light due to the wide opening of the stomata. In the morning and evening, the rate of respiration is equal to the rate of photosynthesis.

4. Supply of water: The protoplasm is saturated with water  So, so the rate of respiration increases in the supply of water and decreases in decreased water as in dry seed.

5. CO₂: An increase in CO₂ concentration decreases the rate of respiration due to the toxic effect of CO₂ in protoplasm.

6. Chemical inhibitors: Chemicals like CN, Azides, CO  CHCl₃, acetone, etc. in very small ququantitiesncrease the rate of respiration. If concentration increases, there is a fall in the rate of respiration then kills the cell.

B) Internal factors:

1. Protoplasmic factors: The rate of respiration depends on uponthe  quantity and quality of the protoplasm of the cell. Younger cells which have more active protoplasm, respire more rapidly than the older cells.

2. Age of plant  The rate of respiration dedecreasesith the age of the plant.

3. Concentration of respiratory matrix:T he rate of respiration depends upon the presence of respiratory materials in the matrix. The rate of respiration iincreaseswith the increase in respiratory substance in the matrix of the cell.