What is the term for the substance upon which enzymes act?

Substrate

Which class of enzymes is involved in oxidation-reduction reactions? A) Transferases B) Hydrolases C) Oxidoreductases D) Lyases

C) Oxidoreductases

Riddle: I am a vital protein that speeds up reactions, but I can be denatured by heat. What am I?

Enzyme

True or False: All enzymes are exclusively made of proteins.

False. Ribozymes are RNA molecules capable of catalyzing biochemical reactions.

Fill in the blank: The active form of an enzyme that includes both the apoenzyme and its non-protein part is called ______.

Holoenzyme

What type of enzyme has both protein and non-protein components?

Complex Enzyme

Which coenzyme is required by Pyruvate Dehydrogenase?

Coenzyme A (CoA)

In enzyme kinetics, what does Vmax represent?

The maximum velocity achievable by the reaction.

Fill in the blank: The Michaelis constant, known as Km, indicates the substrate concentration required to achieve ______.

Half of the maximum reaction velocity (½ Vmax)

True or False: Noncompetitive inhibitors bind to the active site of the enzyme.

False. Noncompetitive inhibitors bind to an allosteric site.

Which enzyme class catalyzes the breakdown of covalent bonds through hydrolysis?

Hydrolases

What is the primary role of allosteric enzymes?

To regulate metabolic pathways by binding modifiers at regulatory sites.

Riddle: I can be modified by the addition of a phosphate group to activate or deactivate enzymes. What process am I involved in?

Covalent modification, specifically phosphorylation.

Fill in the blank: The addition of an acetyl group to a protein is known as ______.

Acetylation

Which type of enzyme inhibition cannot be reversed by increasing substrate concentration?

Noncompetitive Inhibition

What is the effect of increasing temperature on enzyme activity, generally?

It increases the activity up to a certain point but can denature the enzyme if too high.

Which enzyme serves as a marker for liver diseases?

Alanine aminotransferase (ALT)

True or False: Isoenzymes are identical in structure but differ in function.

False. Isoenzymes can differ in both structure and function.

What is the significance of the AST:ALT ratio in diagnosing liver conditions?

It helps indicate conditions causing hepatocellular damage.

Fill in the blank: The process by which enzymes bind substrates and transform them into products is referred to as ______.

Enzyme catalysis

Which enzyme is known to have a prosthetic group that is tightly bound?

Metalloenzyme

Riddle: I change shape when my partner binds me, making me a better fit. What am I?

Allosteric enzyme

What is the role of feedback inhibition in metabolic pathways?

To regulate the activity of enzymes involved in the pathway to prevent overproduction.

Fill in the blank: ______ are antibodies that exhibit catalytic activity.

Abzymes

Which enzyme classification includes ligases?

Ligases join two molecules together in reactions linked to ATP hydrolysis.

True or False: Isoenzymes can vary in their electrophoretic mobility.

True.

What type of enzyme is carbonic anhydrase?

It is a metalloenzyme requiring zinc as a cofactor.

In enzyme kinetics, what does a Lineweaver-Burk plot represent?

It is a graphical representation of enzyme kinetics showing 1/V vs. 1/S.

Riddle: I’m an enzyme that helps in digestion, but my levels rise in response to injury. What am I?

Lactate Dehydrogenase (LDH)

What is the function of serine proteases?

To break down proteins by cleaving peptide bonds.