L.S.1.2 - Enzymes

What occurs to an enzyme after it breaks down a substrate?

• It attaches to another substrate.

• It is broken down and becomes unusable.

• It is slightly altered and binds to a different substrate.

• It changes shape and uses ATP to bind to another substrate.

The balanced equation below summarizes the decomposition of hydrogen peroxide when the enzyme catalase is added: 2H₂O₂ → 2H₂O + O₂(g) Over time it was observed that the production of bubbles decreased. Why did this most likely occur?

• The concentration of the water decreased.

• The concentration of the water increased.

• The concentration of the hydrogen peroxide (H₂O₂) decreased.

• The concentration of the hydrogen peroxide (H₂O₂) increased.

Tags

NGSS.HS-PS1-5

Which equation represents an enzyme’s function in chemical reactions?

• product + substrate → enzyme

• substrate + enzyme → product

• substrate + enzyme → product + enzyme

• product + enzyme → substrate + enzyme

The enzyme beta-galactosidase is involved in a certain biological reaction. How would the reaction be affected if beta-galactosidase becomes unavailable?

• The rate of the reaction will decrease.

• A different enzyme will be used in the reaction.

• Different chemicals will be used to replace the enzyme.

• The reaction will produce more of this enzyme than needed.

Which statement best describes the lock-and-key model of enzyme function?

• Enzymes interact with coenzymes.

• Enzymes raise the activation energy of the reaction.

• Enzymes have an active site that is substrate-specific.

• Enzymes are denatured when there are drastic changes in temperature.

How do enzymes affect biological reactions?

• Enzymes decrease the activation energy required for a reaction, increasing the reaction rate.

• Enzymes decrease the activation energy required for a reaction, decreasing the reaction rate.

• Enzymes increase the activation energy required for a reaction, increasing the reaction rate.

• Enzymes increase the activation energy required for a reaction, decreasing the reaction rate.

How does the graph explain the energy required for this reaction to occur?

• The reaction occurs more slowly in the presence of the enzyme.

• The reaction occurs more rapidly in the presence of the enzyme.

• More energy is required for the reaction to occur in the presence of the enzyme.

• Less energy is required for the reaction to occur in the presence of the enzyme.

Tags

NGSS.HS-PS1-4

Which choice best describes an enzyme in a biological reaction?

• Enzymes are lipids.

• Enzymes work inside cells.

• Enzymes are organic catalysts.

• Enzymes work best at all pH ranges.

In an enzymatic reaction, what will most likely occur if excess product builds up within the system?

• The reaction will speed up.

• The reaction will slow down.

• Excess enzymes will be produced.

• Excess substrate will be produced.

Tags

NGSS.HS-LS1-3

How can enzymes increase the rate of a chemical reaction without breaking down?

• Enzymes increase the temperature of the reactants.

• Enzymes convert substrates into additional enzymes.

• Enzymes recycle themselves to continuously catalyze reactions.

• Enzymes change the products being manufactured during the reaction.