Enzymer

Question 1

What are enzymes?

Answer 1

Enzymes are biological catalysts that speed up chemical reactions in living organisms.

Question 2

True or False: Enzymes are consumed in the reactions they catalyze.

Answer 2

False

Question 3

What is the active site of an enzyme?

Answer 3

The active site is the region on the enzyme where substrate molecules bind and undergo a chemical reaction.

Question 4

Fill in the blank: Enzymes lower the _____ of a chemical reaction.

Answer 4

activation energy

Question 5

What is enzyme kinetics?

Answer 5

Enzyme kinetics is the study of the rates of enzyme-catalyzed reactions.

Question 6

What is the Michaelis-Menten equation used for?

Answer 6

The Michaelis-Menten equation is used to describe the rate of enzymatic reactions with a single substrate.

Question 7

Define Vmax in enzyme kinetics.

Answer 7

Vmax is the maximum rate of an enzymatic reaction when the enzyme is saturated with substrate.

Question 8

What does Km represent in enzyme kinetics?

Answer 8

Km is the Michaelis constant, which represents the substrate concentration at which the reaction rate is half of Vmax.

Question 9

True or False: A lower Km value indicates a higher affinity between the enzyme and the substrate.

Answer 9

True

Question 10

What is a competitive inhibitor?

Answer 10

A competitive inhibitor is a substance that competes with the substrate for binding to the active site of the enzyme.

Question 11

How does a non-competitive inhibitor affect enzyme activity?

Answer 11

A non-competitive inhibitor binds to an enzyme at a site other than the active site, reducing the overall number of active enzymes.

Question 12

Fill in the blank: Enzymes are typically proteins, but some are made of _____.

Answer 12

RNA

Question 13

What role do cofactors play in enzymatic reactions?

Answer 13

Cofactors are non-protein molecules that assist enzymes in catalyzing reactions.

Question 14

What is allosteric regulation?

Answer 14

Allosteric regulation is the process by which the binding of a molecule to a site other than the active site affects enzyme activity.

Question 15

True or False: Enzymes can function at any temperature.

Answer 15

False

Question 16

What effect does temperature have on enzyme activity?

Answer 16

Enzyme activity typically increases with temperature up to a certain point, after which it decreases due to denaturation.

Question 17

What is enzyme denaturation?

Answer 17

Enzyme denaturation is the process where the enzyme loses its three-dimensional structure and, consequently, its activity.

Question 18

What is a substrate?

Answer 18

A substrate is a reactant molecule upon which an enzyme acts.

Question 19

Fill in the blank: The _____ model describes the specific interaction between an enzyme and its substrate.

Answer 19

lock and key

Question 20

What is the difference between a reversible and irreversible inhibitor?

Answer 20

Reversible inhibitors can bind and unbind from the enzyme, while irreversible inhibitors permanently deactivate the enzyme.

Question 21

What is feedback inhibition?

Answer 21

Feedback inhibition is a regulatory mechanism where the end product of a metabolic pathway inhibits an enzyme involved in its synthesis.

Question 22

True or False: Enzymes can catalyze reactions in both directions.

Answer 22

True

Question 23

What is the role of enzyme specificity?

Answer 23

Enzyme specificity refers to the ability of an enzyme to select for a particular substrate among a group of similar molecules.

Question 24

What are zymogens?

Answer 24

Zymogens are inactive enzyme precursors that require a biochemical change to become active.

Question 25

Fill in the blank: Enzyme activity can be affected by changes in _____ and _____ levels.

Answer 25

pH, substrate

Question 26

How do enzyme inhibitors affect the rate of reaction?

Answer 26

Enzyme inhibitors decrease the rate of reaction by preventing the substrate from binding to the enzyme or by reducing the enzyme's activity.

Question 27

What is the significance of the catalytic efficiency of an enzyme?

Answer 27

Catalytic efficiency reflects how effectively an enzyme converts substrate into product and is often represented by the ratio of kcat/Km.

Question 28

True or False: Enzymes are highly specific and can catalyze multiple reactions.

Answer 28

False

Question 29

What is the role of prosthetic groups in enzymes?

Answer 29

Prosthetic groups are tightly bound non-polypeptide units that assist in enzyme function.

Question 30

Define the term 'enzyme turnover number' (kcat).

Answer 30

kcat is the number of substrate molecules converted to product by an enzyme in a given time when the enzyme is fully saturated.

Question 31

What is the effect of increasing substrate concentration on enzyme activity?

Answer 31

Increasing substrate concentration increases enzyme activity until the enzyme becomes saturated.

Question 32

Fill in the blank: The _____ hypothesis describes the dynamic interaction between an enzyme and its substrate.

Answer 32

induced fit

Question 33

What is the role of enzyme inhibitors in drug design?

Answer 33

Enzyme inhibitors can be designed as drugs to target specific enzymes involved in disease processes.

Question 34

True or False: Enzymes can function in extreme conditions, such as high temperatures and acidic pH.

Answer 34

True

Question 35

What is the importance of enzyme regulation?

Answer 35

Enzyme regulation is important for maintaining metabolic balance and responding to changes in cellular conditions.

Question 36

What are the two main types of enzyme kinetics?

Answer 36

The two main types of enzyme kinetics are zero-order and first-order kinetics.

Question 37

Fill in the blank: The _____ effect refers to the phenomenon where the binding of one substrate molecule increases the binding affinity of additional substrate molecules.

Answer 37

cooperativity

Question 38

What is the role of temperature in enzyme reactions?

Answer 38

Temperature affects the kinetic energy of molecules, which influences the rate of enzyme-catalyzed reactions.

Question 39

What are enzyme assays used for?

Answer 39

Enzyme assays are laboratory methods used to measure enzyme activity and kinetics.

Question 40

Define 'enzyme specificity.'

Answer 40

Enzyme specificity is the ability of an enzyme to preferentially catalyze a specific reaction for a particular substrate.

Question 41

What is an enzyme's turnover number (kcat)?

Answer 41

kcat is the maximum number of substrate molecules that one enzyme molecule converts to product per unit time under saturating substrate conditions.

Question 42

True or False: Enzymes are only found in living organisms.

Answer 42

False

Question 43

What is the primary function of enzymes in biological systems?

Answer 43

The primary function of enzymes is to catalyze biochemical reactions, thereby facilitating metabolic processes.