Exam 1 Review Pt 2

What does Km represent in enzyme kinetics?

• The maximum rate of the enzyme-catalyzed reaction

• The concentration of substrate at half-maximum enzyme velocity

• The rate at which the enzyme reaches equilibrium

• The amount of enzyme required to catalyze a reaction

Which of the following conditions would result in the observation of Vmax?

• When the substrate concentration is extremely high

• When the enzyme is saturated with substrate

• When the enzyme concentration is very low

• When the temperature is the enzyme's optimal temperature

Which of the following statements about the Michaelis-Menten equation is correct?

• It assumes that the enzyme-substrate complex reaches a steady-state.

• It describes the relationship between reaction velocity and enzyme concentration.

• It assumes that the formation of the enzyme-substrate complex is irreversible.

• It applies only to allosteric enzymes.

Which of the following would be considered a cofactor rather than a coenzyme?

• Magnesium ion (Mg2+)

• Thiamine pyrophosphate (TPP)

• Nicotinamide adenine dinucleotide (NAD+)

• Coenzyme A

Which of the following enzymes binds to its substrate more often than the other enzymes listed?

• Enzyme A (Km = 6.4 mM)

• Enzyme B (Km = 5.2 mM)

• Enzyme C (Km = 9.1 mM)

• Enzyme D (Km = 2.8 mM)

In enzyme kinetics, when substrate concentration is low, the equation for the reaction rate is ________, and when substrate concentration is high, the equation for the reaction rate is ________.

• Zero-order kinetics; first-order kinetics

• First-order kinetics; second order kinetics

• Second-order kinetics; first-order kinetics

• First-order kinetics; zero-order kinetics

Which ratio defines the catalytic efficiency of an enzyme?

• Km/Kcat

• Kcat/Km

• Vmax/Km

• Kcat/Vmax

Which type of inhibition is represented on this plot?

• uncompetitive inhibition

• noncompetitive inhibition

• competitive inhibition

• mixed inhibition

A scientist is studying a biochemical reaction and determines that it has a negative Gibbs free energy (ΔG). What can she conclude about the reaction?

• The reaction is at equilibrium and will not proceed in either direction.

• The reaction is spontaneous and will proceed forward under standard conditions.

• The reaction requires an input of energy to proceed.

• The reaction has a high activation energy and will not occur without an enzyme.

Tags

NGSS.HS-PS1-4

What is the enthalpy change (ΔH) when chemical bonds are broken?

• ΔH is negative because energy is released.

• ΔH is zero because bond breaking does not require energy.

• ΔH is positive because energy is absorbed.

• ΔH depends on the type of bond but is usually negative.

Tags

NGSS.HS-PS1-4