7. Energy and Metabolism

What is meant by the "induced fit" of an enzyme?

What is meant by the term induced fit?

Label the parts of the following diagram illustrating the catalytic cycle of an enzyme.

Which of the following correctly describe an active site? Select True or False for each statement. T/F It is the location in an enzyme where substrates bind. T/F It is the place where a molecule or ion binds to an inactive enzyme to induce a shape change to make it active. T/F It is the portion of an enzyme where chaperones bind to help enzymes fold. T/F It is the site on an enzyme where catalysis occurs.

Explain the lock-and-key model of enzyme activity. What is incorrect about this model?

Enzymes speed up chemical reactions by                   . a. heating cells; b. binding to substrates and placing stress on their bonds; c. changing the shape of the cell; d. supplying energy to the substrate

You have discovered an enzyme that appears to function only when a particular sugar accumulates. Which of the following scenarios would you predict to be responsible for activating this enzyme? a. The sugar cleaves the enzyme to form the active conformation. b. The sugar is an allosteric regulatory molecule for the enzyme. c. The sugar is a competitive inhibitor for the enzyme. d. The sugar phosphorylates the enzyme to form the active conformation

Your body makes NAD+ and FAD from two B vitamins, niacin and riboflavin. The Recommended Dietary Allowance is 20 mg for niacin and 1.7 mg for riboflavin. These amounts are thousands of times less than the amount of glucose your body needs each day to fuel its energy needs. Why is the daily requirement for these vitamins so small?