Biochemistry Lecture 1: Enzymes

What is the role of an enzyme in a biological reaction?

To speed up the reaction without being changed (correct)
To act as a substrate in the reaction
To slow down the reaction
To change the substrate into a product

What is the result of malfunctions in enzyme reactions?

Drugs are developed to treat the disease
The state of the organism becomes metabolically active
Diseases occur (correct)
The state of the organism becomes metabolically inactive

What is the mechanism of HIV1 protease inhibitors?

They bind to the active site and cleave the polypeptide substrate
They act as a substrate for the enzyme
They bind to the active site and block the enzyme's activity (correct)
They change the substrate into a product

What is the importance of enzymes in biological processes?

They are involved in all biological processes (B) Signup and view all the answers

What is the term for the area of the enzyme where substrate(s) bind?

Active site (B) Signup and view all the answers

What is the purpose of catalysis in biological reactions?

To control the reaction (A) Signup and view all the answers

What is the primary function of biological catalysts, such as enzymes?

To speed up chemical reactions by reducing the activation energy (B) Signup and view all the answers

What is the term for the minimum energy required for a reaction to occur?

Activation energy (C) Signup and view all the answers

What is the purpose of measuring enzyme activity?

To understand the rate of a reaction (A) Signup and view all the answers

What is the term for the state in which the reactants and products are equally balanced?

Equilibrium (A) Signup and view all the answers

What is the characteristic of an enzyme's active site that allows it to bind to a specific substrate?

Induced fit (C) Signup and view all the answers

What is the term for the measure of disorder or randomness in a system?

Entropy (D) Signup and view all the answers

What is the primary reason for starting with a high concentration of substrate and a much lower concentration of enzyme?

To ensure the enzyme is fully saturated (D) Signup and view all the answers

What is being measured in an enzyme kinetics experiment?

The decrease in substrate or the increase in product (D) Signup and view all the answers

What is the purpose of measuring the reaction rate at different starting substrate concentrations?

To determine the Km value (B) Signup and view all the answers

What is the complex formed during the enzyme-catalyzed reaction?

ES (B) Signup and view all the answers

What is the equation that represents the enzyme-catalyzed reaction?

E + S → ES → EP → E + P (D) Signup and view all the answers

What can be measured during an enzyme-catalyzed reaction?

The decrease in substrate and the increase in product (D) Signup and view all the answers

What is the difference between the substrate and product in the catalase reaction?

The substrate is a liquid, while the product is a gas (D) Signup and view all the answers

Why can NITROSEFIN be used to study the degradation of penicillin by β-lactamase?

Because NITROSEFIN is a colored molecule that changes intensity during the reaction (C) Signup and view all the answers

What is the role of the enzyme catalyst in the reaction?

To speed up the reaction without being consumed (D) Signup and view all the answers

What is a common feature of many substrates and products in biology?

They absorb specific wavelengths of light (B) Signup and view all the answers

What is the purpose of measuring the amount of time the enzyme is bound to the substrate?

To determine the rate of the reaction (B) Signup and view all the answers

Why do we need to use a spectrophotometer to measure the rate of an enzyme-catalysed reaction?

Because many enzymes absorb in the ultraviolet range (A) Signup and view all the answers

What is the purpose of using a stopped flow method in enzyme kinetics?

To measure the rate of very fast reactions (B) Signup and view all the answers

What is the significance of the maximum rate of an enzyme-catalysed reaction?

It is the fastest rate that the reaction can go in the presence of the enzyme (C) Signup and view all the answers

What is the importance of understanding the affinity of an enzyme for its substrate?

It determines how well the substrate binds to the active site (A) Signup and view all the answers

What is the purpose of electrophoresis in enzyme kinetics?

To separate big fragments from small fragments (C) Signup and view all the answers

What is the significance of using a high concentration of substrate and a low concentration of enzyme in enzyme kinetics experiments?

To ensure that the enzyme is fully saturated with substrate (B) Signup and view all the answers