State the role of enzymes in metabolic pathways. (b) Explain why metabolic reactions occur in gentle steps. (c) Describe the stages of the light independent reactions in a typical C3 plant. (d) Differentiate between C3 and C4 plants.

1. (a) State the role of enzymes in metabolic pathways.

Enzymes are biological catalysts that speed up the rate of biochemical reactions in metabolic pathways without being consumed in the process. They do this by lowering the activation energy required for the reactions to occur. Each enzyme is specific to a particular substrate and reaction.