Exam 6: The Behavior of Proteins: Enzymes

Which of the following is true concerning a ping-pong mechanism?

Which of the following is true about lactate dehydrogenase (LDH)?

Exhibit 6A This is a reaction going on in your muscle cells right this very minute: The enzyme triose phosphate isomerase catalyzes this reaction in the forward direction as part of the glycolytic pathway. It follows simple Michaelis-Menten kinetics: Typical cellular concentrations: triose phosphate isomerase = 0.1 nM?dihydroxyacetone phosphate = 5 µM glyceraldehyde-3-phosphate = 2 µM $k_{1}=10^{8} \mathrm{M}^{-1} \mathrm{~s}^{-1}, k_{-1}=100 \mathrm{~s}^{-1}, k_{2}=900 \mathrm{~s}^{-1}$ -Refer to Exhibit 6A. What is the equilibrium constant for the uncatalyzed reaction?

Which of the following diseases has not been successfully treated using the principles of enzyme inhibition?

The fundamental difference between competitive and noncompetitive inhibition is

The drug acetazolamide:

Which of the following are related for a given enzyme?

Irreversible inhibitors of enzymatic reactions

In the induced-fit model of substrate binding to enzymes

Generally speaking, a competitive inhibitor and the substrate cannot both bind to the enzyme at the same time.

Non-competitive inhibitors have this effect:

Which of the following is true?

Exhibit 6A This is a reaction going on in your muscle cells right this very minute: The enzyme triose phosphate isomerase catalyzes this reaction in the forward direction as part of the glycolytic pathway. It follows simple Michaelis-Menten kinetics: Typical cellular concentrations: triose phosphate isomerase = 0.1 nM?dihydroxyacetone phosphate = 5 µM glyceraldehyde-3-phosphate = 2 µM $k_{1}=10^{8} \mathrm{M}^{-1} \mathrm{~s}^{-1}, k_{-1}=100 \mathrm{~s}^{-1}, k_{2}=900 \mathrm{~s}^{-1}$ -Refer to Exhibit 6A. What is the actual velocity of the forward reaction under physiologic conditions?

The initial rate of an enzymatic reaction is usually determined in order to assure that

The E-S complex often shows as a slight depression in the energy profile for the reaction.

The substrate will only bind to the enzyme when the shapes fit together rigidly.

Exhibit 6A This is a reaction going on in your muscle cells right this very minute: The enzyme triose phosphate isomerase catalyzes this reaction in the forward direction as part of the glycolytic pathway. It follows simple Michaelis-Menten kinetics: Typical cellular concentrations: triose phosphate isomerase = 0.1 nM?dihydroxyacetone phosphate = 5 µM glyceraldehyde-3-phosphate = 2 µM $k_{1}=10^{8} \mathrm{M}^{-1} \mathrm{~s}^{-1}, k_{-1}=100 \mathrm{~s}^{-1}, k_{2}=900 \mathrm{~s}^{-1}$ -Refer to Exhibit 6A. What is the K_M of the enzyme?

Which of the following is true about a mixed type inhibition?

Enzymatic activity has an optimum temperature because

Exhibit 6A This is a reaction going on in your muscle cells right this very minute: The enzyme triose phosphate isomerase catalyzes this reaction in the forward direction as part of the glycolytic pathway. It follows simple Michaelis-Menten kinetics: Typical cellular concentrations: triose phosphate isomerase = 0.1 nM?dihydroxyacetone phosphate = 5 µM glyceraldehyde-3-phosphate = 2 µM $k_{1}=10^{8} \mathrm{M}^{-1} \mathrm{~s}^{-1}, k_{-1}=100 \mathrm{~s}^{-1}, k_{2}=900 \mathrm{~s}^{-1}$ -Refer to Exhibit 6A. "Hindrate" is an inhibitor of triose phosphate isomerase. When it is added to cells at a concentration of 0.1 nM, the enzyme's K_M for the substrate is unchanged, but the apparent V_max is altered to 50 nM/sec. In the following graph, which line best represents the Lineweaver-Burk plot obtained in the presence of hindrate?