Practice Questions

Enzyme activity depends on maintaining proper structural integrity and environmental conditions. Even with abundant substrate, unsuitable temperature or pH reduces catalytic efficiency.

Initially, substrate concentration limits the reaction. After saturation, enzyme concentration becomes the limiting factor.

Cold-adapted enzymes function efficiently at low environmental temperatures and are less stable at higher temperatures.

Extremely alkaline conditions may permanently disrupt the enzyme's tertiary structure, preventing recovery of activity.

At Vmax, enzyme saturation has occurred. Additional substrate cannot increase the reaction rate.

Increasing substrate concentration increases the likelihood that substrate molecules encounter enzyme active sites.

Each enzyme has unique active-site residues whose catalytic function depends on a specific protonation state.

When substrate is abundant, all enzyme molecules can function at maximum capacity, making enzyme concentration the principal variable.

Excessive heat disrupts hydrogen bonds and hydrophobic interactions, leading to denaturation and loss of catalytic activity.

More substrate molecules increase the frequency of effective collisions with enzyme active sites until saturation is reached.