A cell may vary the rate of an enzyme controlled reaction by making more/less or degrading more/less.
Explanation:
A cell may vary the rate of an enzyme controlled reaction by making more/less or degrading more/less. Several factors affect the rate at which enzymatic reactions proceed include post translational modifications, substrate concentration, cofactors, temperature, pH, locations. The shape and structure of the enzyme will change as the pH value of the reaction medium changes.
1. chlorophyll : because animals cannot produce their own food
2. Tonoplast: it is a membrane that surrounds the large vacuole in a mature plant cell and vacuoles are not present in animals cell or if present little