Free Enzymes MCQs with Answers

• A. Cofactor
• B. Catalytic site
• C. Coenzyme
• D. Binding site

Explanation: Active site contains two sites binding site and catalytic site. Binding site is responsible for the formation of ES complex.

• A. Stop
• B. Be slowed down
• C. Not affected
• D. Carried out at faster rate

Explanation: The biological processes that occur within all living organisms are chemical reactions, and enzymes regulate most.

• A. Prosthetic group
• B. Coenzyme
• C. Activator
• D. Inhibitor

Explanation: Mg+2 acts as an activator in this context by binding to the enzyme, promoting its catalytic activity for the substrate.

• A. Mouth
• B. Testes
• C. Large intestine
• D. Stomach

Explanation: Enzymes that require an optimum temperature lower than 37°C for their proper functioning are present in the testes.

• A. DNA polymerase
• B. Adenylate cyclase
• C. Phosphoprotein phosphatase
• D. Nitric oxide synthetase

Explanation: Option A is correct since Calcium ions is the non-reactive cofactor for DNA polymerase.

• A. Substrate
• B. Enzymes
• C. End product
• D. Temperature

Explanation: Among the options you provided, the end product is responsible for inhibiting the enzymatic process during feedback.

• A. Cyanide and Cytochrome reaction
• B. Sulpha drugs and Folic acid synthesizer bacteria
• C. Allosteric inhibition of hexokinase by glucose 6-­phosphate
• D. The reaction between succinic dehydro­genase and succinic acid

Explanation: The correct answer is: Allosteric inhibition of hexokinase by glucose 6­-phosphate.Feedback inhibition is a regulatory mechanism in which…

• A. Cofactor
• B. Catalytic site
• C. Coenzyme
• D. Binding site

Explanation: Active site contains two binding sites and catalytic sites. Binding site is responsible for the formation of Es complex.

• A. Emil Fischer
• B. Koshland
• C. Watson and Crick
• D. Rosalind Franklin

Explanation: The correct answer is Emil Fischer, who proposed the lock and key model, which describes how enzymes are specifically shaped to fit…

• A. Irreversible inhibitors
• B. Reversible inhibitors
• C. Competitive inhibitors
• D. Non-competitive inhibitors

Explanation: The correct answer is Irreversible inhibitors because these inhibitors form covalent bonds with the enzyme's active site, leading to a…

• A. The competitive inhibitor does not affect the rate of breakdown of the enzyme-substrate complex
• B. The presence of the competitive inhibitor decreases the Km of the enzyme for the substrate
• C. A competitive inhibitor reacts reversibly with the enzyme to form an enzyme-inhibitor complex
• D. In competitive inhibition, the inhibitor molecule is not chemically changed by the enzyme

Explanation: In competitive inhibition, the inhibitor competes with the substrate for the active site of the enzyme.

• A. The substrate binds with the enzyme at its active site
• B. The addition of a lot of succinates does not reverse the inhibition of succinic dehydrogenase by malonate
• C. A non-competitive inhibitor binds the enzyme at a site distinct from that which binds the substrate
• D. Malonate is a competitive inhibitor of succinic dehydrogenase

Explanation: The reduction of the activity of succinate dehydrogenase by malonate is an example of competitive inhibition.

• A. It is a globular protein
• B. Increases the energy of activation
• C. Remains unchanged after reaction
• D. Speeds up the reaction

Explanation: Enzymes are biological catalysts that significantly increase the rate of chemical reactions by lowering the activation energy required for…

• A. Attached with organelles
• B. In cytoplasm
• C. Free floating
• D. In coagulated form

Explanation: Enzymes play a crucial role in catalyzing biochemical reactions, and their effectiveness is often dependent on their localization within…

• A. All enzymes require co-factors for proper functioning.
• B. Only a small amount of enzymes is required to catalyze reactions.
• C. They function under both in vitro and in vivo conditions.
• D. They lower the activation energy of reactions.

Explanation: The statement 'All enzymes require cofactors for proper functioning' is false.

• A. Allosteric site
• B. Globular site
• C. Reactive site
• D. Active site

Explanation: The reaction takes place in the active site of an enzyme. The active site is a specific region within the enzyme where the substrate binds…

• A. Apoenzyme
• B. Coenzymes
• C. Activator
• D. Prosthetic group

Explanation: If the cofactor is a non-protein molecule like a metallic ion, it is referred to as an activator.

• A. Activator
• B. Coenzyme
• C. Co-factor
• D. Prosthetic group

Explanation: A coenzyme is defined as a non-protein organic molecule that associates with an enzyme and assists in catalyzing biochemical reactions.

• A. Activator
• B. Prosthetic group
• C. Coenzyme
• D. Apo-enzyme

Explanation: A prosthetic group is a non-polypeptide unit tightly and permanently bound to an enzyme, contributing to its function.

• A. Extra factor
• B. Efficient co-factor
• C. Additional factor
• D. Co-factor

Explanation: A co-factor is a non-protein molecule required for the proper functioning of enzymes.