Exam 6: Mechanisms of Enzymes

What shape would a graph of reaction velocity versus pH have for an enzyme that uses both a proton donor and a proton acceptor during catalysis both acid and base catalysis)?

The relative orientation of colliding molecules only affects reactions rates when the energy during impact is low. If the energy of impact is high enough, orientation is unimportant.

The catalytic triad of chymotrypsin and other serine proteases consists of

In the Ser-His-Asp catalytic triad in serine proteases, the serine residue serves as an acid-base catalyst, while the histidine residue serves as a covalent catalyst.

On the energy diagram below, which arrows) represent the activation energy for the forward and reverse reactions?

How many intermediates are indicated by the energy diagram below?

Radicals are stable, unreactive species that have an unpaired electron.

Some antibody molecules are enzymatic if they are formed against

Experiments on the bacterial serine protease subtilisin show that even when all three residues of the catalytic triad are mutated, the catalytic rate of the enzyme is still 3000 times the uncatalyzed reaction rate. Which mode of catalysis is likely responsible for this remaining catalytic activity?

Induced fit studies by Koshland using the enzyme hexokinase showed that there are enzyme forms

A thermodynamic pit occurs when

Replacement of the amino acid at or near an active site of an enzyme is more likely to change enzyme activity than the replacement of at or near the active site.

A chemical group that has a negative charge or an unshared electron pair is called aan)

In the reaction below Y^- is . Y^- + CH₂X → CH₂Y + X^-

What is the biological function of lysozyme?

The enzyme has an active site which

A detailed description of a chemical reaction in terms of the molecular, atomic or subatomic events is called the reaction .

Cleavage of a C-C bond produces a carbanion that both electrons and a carbocation that both electrons.

The role of serine at the active site of serine proteases is to act as an) catalyst, while the histidine residue serves as an) catalyst.

Transitions states bind to their enzymes more tightly than their substrates do.