Energy, Enzymes, and Metabolism

These flashcards cover key vocabulary terms related to metabolism, energy, and enzymatic activity.

Metabolism

The set of life-sustaining chemical reactions that include anabolic and catabolic reactions.

Anabolism

The metabolic process that builds up molecules and requires energy.

Catabolism

The metabolic process that breaks down molecules and releases energy.

Kinetic Energy

The energy an object possesses due to its motion.

Potential Energy

Stored energy based on an object's position or state.

First Law of Thermodynamics

Energy cannot be created or destroyed, only transformed from one form to another.

Second Law of Thermodynamics

In any energy transfer, there will always be a loss of usable energy, increasing the entropy of the system.

Free Energy (G)

The amount of energy available to do work in a system.

Entropy (S)

A measure of the disorder or randomness in a system.

Exergonic Reactions

Reactions that release free energy, characterized by a negative change in free energy (∆G < 0).

Endergonic Reactions

Reactions that absorb free energy, characterized by a positive change in free energy (∆G > 0).

Enzymes

Biological catalysts that accelerate chemical reactions by lowering the activation energy.

Activation Energy (EA)

The minimum amount of energy required to start a chemical reaction.

Substrate

The reactant molecule that an enzyme acts upon.

Enzyme-Substrate Complex

The temporary complex formed when an enzyme binds to its substrate.

Allosteric Enzymes

Enzymes that are regulated by the binding of molecules at sites other than the active site.

Cofactors

Non-protein molecules that assist enzymes in catalyzing reactions.

Coenzymes

Organic cofactors that help enzymes; often derived from vitamins.

Competitive Inhibition

A form of enzyme inhibition where an inhibitor competes with the substrate for the active site.

Noncompetitive Inhibition

A form of enzyme inhibition where an inhibitor binds to an enzyme at a site other than the active site.

Feedback Inhibition

A regulatory mechanism in which the end product of a metabolic pathway inhibits an earlier step.

Isozymes

Different forms of an enzyme that catalyze the same reaction but may have different properties.