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 uncatalysed reaction?

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?

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

Enzymes bind weakly to the substrate and product of a reaction but much more strongly to the molecular species with the highest free energy along the reaction pathway (between substrate and product).

This catalysis strategy is called:

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

The enzyme concentration used was 10 nM (0.01 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 a table listing the initial rate of an enzyme-catalysed reaction at various substrate concentrations.

The enzyme concentration used was 1 nM (0.001 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.

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 = 200 μM s^-1
• K_m = 2 mM

If the same reaction is repeated but using a chymotrypsin concentration of 0.05 μM, what will be the values of V_max, K_m, and k_cat under these new conditions?

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

The enzyme concentration used was 1 nM (0.001 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.

A specific amino acid side chain in the active site of the enzyme can undergo a chemical reaction with a particular functional group on the substrate, giving rise to a covalent intermediate that later breaks down to release the product.

This catalysis strategy is called:

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

The enzyme concentration used was 10 nM (0.01 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 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 enzyme-product complex?