Photosynthesis and Enzymes

What is activation energy?

• Activation energy is the minimum amount of energy required to start a chemical reaction.
• Activation energy is the energy released during a chemical reaction.
• Activation energy is the energy required to stop a chemical reaction.
• Activation energy is the energy stored in a chemical compound.

Answer explanation

Tags

NGSS.HS-PS1-5

What role does a catalyst (AKA enzyme) play in a chemical reaction?

• A catalyst increases the activation energy required for the reaction.

• A catalyst changes the direction of the chemical reaction.

• A catalyst provides the reactants for the chemical reaction.

• A catalyst lowers the activation energy required for the reaction.

Answer explanation

What does induced fit mean?

• Enzyme remains unchanged when binding with the substrate
• Active site of an enzyme changes shape upon binding with the substrate
• Substrate changes shape to fit the enzyme's active site
• Induced fit is not related to enzyme-substrate interactions

Answer explanation

How does temperature generally affect enzyme activity?

• Temperature has no effect on enzyme activity

• Increasing temperature always increases enzyme activity

• There is an optimal temperature range for enzyme activity, beyond which activity decreases

• Decreasing temperature always increases enzyme activity

Answer explanation

How do cofactors influence enzyme activity?

• Cofactors irreversibly inhibit enzymes, stopping their function

• Cofactors bind to enzymes, changing their structure and enhancing their activity

• Cofactors serve as the primary substrate for all enzymatic reactions

• Cofactors compete with substrates, reducing enzyme activity

Answer explanation

How do competitive inhibitors affect enzyme activity?

• They increase the activation energy required for the reaction.

• They bind to the enzyme's active site, preventing the substrate from binding.

• They bind to a site other than the active site, changing the enzyme's shape.

• They provide an alternative pathway for the reaction with a lower activation energy.

Answer explanation

How do noncompetitive inhibitors affect enzyme activity?

• Noncompetitive inhibitors increase enzyme activity by binding to the active site.
• Noncompetitive inhibitors have no effect on enzyme activity.
• Noncompetitive inhibitors reduce enzyme activity by binding to a site other than the active site.
• Noncompetitive inhibitors only bind to the substrate.

Answer explanation

What is the effect of pH on enzyme activity?

• pH has no effect on enzyme activity.

• Enzyme activity increases as pH levels increase indefinitely.

• There is an optimal pH at which an enzyme's activity is highest, and deviations from this pH can decrease activity.

• Decreasing pH always increases enzyme activity.

Answer explanation

What is negative feedback (in relation to enzymes)?

• A process where enzymes enhance the production of a specific product
• A regulatory mechanism where the end product of a metabolic pathway inhibits an earlier step in the pathway, ultimately reducing the production of that product.
• A feedback loop that increases the activity of enzymes
• A mechanism where enzymes are permanently deactivated

Answer explanation

The minimum amount of energy required by a reacting molecule to get converted into a product

Answer explanation