Question

the figure below shows the effect of temperature on enzyme activity. why does the enzyme have lower activity at 10°c than at 40°c?
at 10°c, the enzyme and substrate have low kinetic energy, they have less contact and consequently less products formed.
at 10°c, the enzyme is denatured.
at 10°c, the enzyme does not like the substrate.
at 10°c, the enzyme is inhibited by a competitive inhibitor.

Explanation:

Enzymes are proteins that catalyze biochemical reactions. Their activity is influenced by temperature. At lower temperatures like \(10^{\circ}C\), molecules (enzyme and substrate) have less kinetic energy. Kinetic energy is related to the movement of molecules. With less movement (lower kinetic energy), there are fewer collisions between the enzyme and its substrate. Enzyme - substrate collisions are necessary for the formation of the enzyme - substrate complex, which then leads to the formation of products. At \(40^{\circ}C\) (closer to the optimum temperature in the given graph), the enzyme and substrate have more kinetic energy, resulting in more frequent collisions and more products formed.
Denaturation of enzymes (a change in their three - dimensional structure that makes them non - functional) usually occurs at higher temperatures (not at \(10^{\circ}C\) as the graph shows some activity at \(10^{\circ}C\)). The idea of an enzyme “not liking” a substrate is a non - scientific anthropomorphic description. There is no indication from the problem (such as a mention of adding a new substance) that a competitive inhibitor is present at \(10^{\circ}C\).

Answer:

At \(10^{\circ}C\), the enzyme and substrate have low kinetic energy, they have less contact and consequently less products formed.