Metabolism and Enzyme Activity Review

This set of flashcards covers key concepts related to metabolism, enzyme activity, and specific biochemical principles that were discussed in the lecture.

What is metabolism?

The totality of the reactions in a living cell that involve biochemical modification of organic molecules, leading to the transformation of matter and energy.

What does the first law of thermodynamics state?

The principle of conservation of energy.

What does the second law of thermodynamics state?

The total disorder (entropy) of a system and its surroundings always increases.

What is free energy (ΔG)?

The energy that can do work in a living cell at constant temperature and pressure.

What does a negative ΔG indicate?

It indicates that the process is spontaneous.

How do exergonic and endergonic reactions differ?

An exergonic reaction is spontaneous with a negative ΔG, while an endergonic reaction is nonspontaneous with a positive ΔG.

What is the role of activation energy (EA) in reactions?

Activation energy is the energy needed to start a reaction.

What is ATP and its role in metabolism?

ATP (adenosine triphosphate) is the primary energy currency of the cell, used to drive endergonic reactions.

What is the induced-fit model?

It states that both an enzyme and substrate undergo conformational changes upon binding, which increases the reaction rate.

What mechanisms do enzymes use to stabilize the transition state?

1. Bring reacting molecules together. 2. Expose reactants to altered charge environments. 3. Change the shape of substrate molecules.

What are cofactors?

Cofactors are substances required by many enzymes to function, including metallic ions and small organic molecules.

What is feedback inhibition in enzyme activity?

It is when an end product of a metabolic pathway inhibits an enzyme that acts early in the pathway to regulate its activity.

What is competitive inhibition?

A type of enzyme inhibition where an inhibitor competes with the substrate for binding at the active site.

What is noncompetitive inhibition?

A type of enzyme inhibition where an inhibitor binds to an allosteric site, changing the enzyme's shape and reducing its activity.

How can local conditions affect enzyme activity?

Factors such as substrate concentration, temperature, and pH can significantly affect the rate of enzyme-catalyzed reactions.

What are serine protease inhibitors used for in the context of SARS-CoV-2?

They are investigated as potential treatments to inhibit TMPRSS2, a serine protease involved in viral entry into cells.