When added to a solution at an enzyme concentration of 0.1 μM, chymotrypsin catalyses the hydrolysis of a peptide substrate with the following V_max and K_m values.

• V_max = 300 μM s^-1
• K_m = 3 mM

If the same reaction is repeated but using a chymotrypsin concentration of 0.2 μM, what will be the values of V_max, K_m, and k_cat under these new conditions?

Shown below (left) is a schematic diagram representing the conformational equilibrium of a heteromeric allosteric enzyme. Note that the R state has higher catalytic activity than the T state.

Also shown below (right) are the kinetics curves for this enzyme alone and in the presence of an allosteric modulator.

Based on the kinetics curves, which site on the enzyme (A-D) is this modulator likely to bind to most strongly?

Shown below is a free energy diagram representing a generic reaction of a substrate (S) to give a product (P), in the absence and presence of an enzyme.

Specific points on the free energy diagram are labelled A-D.

Free energy differences are labelled by arrows 1-14 on the right with the following colour code:

• Black: Transitions between S and P
• Red: Other transitions to/from S
• Cyan: Other transitions to/from P

[Note that a free energy difference is defined as the free energy of the destination (arrow head) minus the free energy of the origin (arrow tail)].

Which point represents the transition state of the enzyme-catalysed reaction?

Shown below is a table listing the initial rate of an enzyme-catalysed reaction at various substrate concentrations.

The enzyme concentration used was 100 nM (0.1 μM).

What is the K_m value for this reaction?

Type your answer as a number in the same units listed in the table.

Do not type the units or any other additional characters.

Shown below is the Lineweaver-Burk (double reciprocal) plot for an enzyme-catalysed reaction carried out in the presence of three different concentrations of the same inhibitor.

Which of the following statements regarding the interactions of this inhibitor is most likely to be correct?

Shown below is a table listing the initial rate of an enzyme-catalysed reaction at various substrate concentrations.

The enzyme concentration used was 100 nM (0.1 μM).

What is the k_cat value for this reaction?

Type your answer as a number in units of min^-1.

Do not type the units or any other additional characters.

One strategy used by enzymes to catalyse biochemical reactions is described below.

Amino acid side chains in the active site of an enzyme can protonate or deprotonate functional groups on the substrate, thus providing a pathway to the product that does not readily occur in the absence of the enzyme.

This catalysis strategy is called:

Select the term that best fits in the blank space to make the following statement correct.

By facilitating the conversion of one molecule to another many times repeatedly, an enzyme exhibits the property of _______________ .

The graph below displays a set of kinetics data for an enzyme that follows Michaelis-Menten kinetics.

Estimate the V_max value (in units of μM/s) for this data set.

Note: You should type the number only (not the units or any other characters).

The graph below displays a set of kinetics data for an enzyme that follows Michaelis-Menten kinetics.

Estimate the K_m value (in units of mM) for this data set.

Note: You should type the number only (not the units or any other characters).