Question

1. how does the addition of an enzyme affect a chemical reaction? 2. how does adding more substrate effect an enzyme reaction? 3. which of the following choices, a b c or d, best describes the enzyme reaction graph below? justify your choice.

Explanation:

Step1: Understand enzyme - reaction relationship

Enzymes are biological catalysts. They lower the activation energy of a chemical reaction. This allows the reaction to proceed more easily and at a faster rate. Without an enzyme, a higher amount of energy is required for the reactants to reach the transition - state and form products.

Step2: Analyze substrate - enzyme relationship

Adding more substrate to an enzyme - catalyzed reaction initially increases the reaction rate. This is because more substrate molecules can bind to the available enzyme active sites. However, once all the enzyme active sites are saturated (point B on the graph), adding more substrate does not increase the reaction rate further (plateau from B - C on the graph).

Step3: Answer question 3 (assuming choices are provided)

Since the choices for question 3 are not given, we cannot provide a specific answer. But in general, to justify a choice for an enzyme - reaction graph, one should consider aspects like the initial increase in reaction rate with substrate concentration (due to more substrate - enzyme binding), the saturation point (where all enzymes are occupied), and any other relevant features of the graph such as the shape of the curve.

Answer:

1. An enzyme lowers the activation energy of a chemical reaction, increasing the reaction rate.
2. Initially, adding more substrate increases the enzyme - reaction rate until enzyme active sites are saturated, after which the rate remains constant.
3. No answer provided due to lack of choices.