Answer:
The active site refers to the region present in an enzyme where the binding of the substrate takes place, and the chemical reaction occurs. The amino acids of the enzyme protein combine with the substrate in the active site. Hence, for question 1 the correct answer is option A.
The two kinds of metabolic reactions occur in the cell, that is, catabolism and anabolism. In the anabolic reactions, the energy is consumed, and the small molecules combine to produce the bigger ones. Hence, for question 2 the correct answer is option C.