Enzyme Inhibition and Metabolic Pathways

The video explores enzymes, their roles in catalyzing reactions, and the differences between intracellular and extracellular enzymes. It discusses energy conversion in metabolic reactions, highlighting the inefficiency and heat production. The video explains linear and cyclical metabolic pathways, focusing on glycolysis and the Krebs cycle. It covers enzyme inhibition, including competitive, non-competitive, and feedback inhibition, and concludes with mechanism-based inhibition, emphasizing its irreversible nature and potential dangers.

What is the primary difference between intracellular and extracellular enzymes?

• Intracellular enzymes function outside the body.

• Intracellular enzymes catalyze reactions inside cells.

• Extracellular enzymes are found within cells.

• Extracellular enzymes are not involved in digestion.

How do enzymes facilitate chemical reactions?

• By increasing the temperature of the reaction.

• By lowering the activation energy required.

• By making reactions 100% efficient.

• By converting all energy into chemical energy.

What happens to the energy that is lost as heat during metabolic reactions?

• It is stored in the body for later use.

• It disappears completely.

• It is used to warm the environment.

• It is converted back into ATP.

What is a characteristic of a linear metabolic pathway?

• It can only occur once.

• The reactants and products are the same.

• It requires only one enzyme.

• It involves a series of enzymes modifying a substrate in sequence.

Which process is an example of a cyclical metabolic pathway?

• Glycolysis

• Krebs cycle

• Digestion

• Protein synthesis

Which of the following is true about competitive inhibitors?

• They bind to the allosteric site.

• They permanently deactivate the enzyme.

• They increase the rate of enzyme reactions.

• They compete with the substrate for the active site.

How do non-competitive inhibitors affect enzyme activity?

• They change the shape of the enzyme, affecting its function.

• They bind to the active site.

• They increase the enzyme's affinity for the substrate.

• They are always reversible.

What is the role of feedback inhibition in enzyme activity?

• It helps regulate enzyme activity by using the product to inhibit the enzyme.

• It prevents the enzyme from ever functioning again.

• It speeds up enzyme reactions indefinitely.

• It only occurs in the presence of heavy metals.

What is a potential danger of mechanism-based inhibitors?

• They permanently deactivate enzymes, which can be toxic.

• They are used to increase enzyme activity.

• They can be easily reversed.

• They only affect non-essential enzymes.

Which of the following is an example of a mechanism-based inhibitor?

• Penicillin

• Threonine

• ATP

• Statins