Energy and Enzymes

Flashcards covering key concepts related to energy, enzymes, and thermodynamics, including definitions and important terms.

Enzyme

A biological catalyst that speeds up the rate of a chemical reaction without being consumed in the process.

Activation Energy

The minimum energy required to initiate a chemical reaction by reaching the transition state.

Catalysis

The increase in reaction rate due to the presence of a catalyst.

Metabolism

The collection of all chemical reactions that occur within a cell or organism.

Catabolic Pathway

A metabolic pathway that breaks down larger molecules into smaller ones, releasing energy.

Anabolic Pathway

A metabolic pathway that builds larger, more complex molecules from simpler ones, requiring energy.

Gibbs Free Energy (G)

The amount of energy available in a system to do work, calculated as G = H - TS.

Entropy (S)

A measure of disorder or randomness in a system; in thermodynamics, it reflects the degree of energy dispersion.

Exothermic Reaction

A chemical reaction that releases heat energy, typically resulting in products that have lower enthalpy than the reactants.

Endothermic Reaction

A chemical reaction that absorbs heat energy, resulting in products that have higher enthalpy than the reactants.

Feedback Inhibition

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

Substrate

The reactant molecule upon which an enzyme acts.

Active Site

The specific region of an enzyme where substrate molecules bind and undergo a chemical reaction.

Allosteric Regulation

Regulation of an enzyme's activity through binding of regulatory molecules at sites other than the active site.

Noncompetitive Inhibitor

A molecule that binds to an enzyme at a site other than the active site, reducing its activity regardless of substrate concentration.

Competitive Inhibitor

A molecule that resembles the substrate and competes for binding at the active site of an enzyme, decreasing enzyme activity.

Thermodynamics

The branch of science that studies energy transformations in physical and chemical processes.