Energy, Enzymes, and Metabolism Study Notes

This set of flashcards covers vocabulary and key concepts from the lecture on energy, enzymes, and metabolism.

Thermodynamics

Branch of chemistry concerned with energy changes.

Energy

The capacity to do work (or cause change or supply heat) exists in kinetic and potential states.

Kinetic Energy

Energy of motion, measured as temperature.

Potential Energy

Stored energy determined by an object's position.

First Law of Thermodynamics

Energy cannot be created or destroyed; it can only change forms.

Second Law of Thermodynamics

Entropy (disorder) is continuously increasing; energy transformations proceed to convert matter from a more ordered to a less ordered form.

Endergonic Reactions

Reactions that require energy to proceed; non-spontaneous (ΔG > 0).

Exergonic Reactions

Reactions that release energy and are spontaneous (ΔG < 0).

Activation Energy

Extra energy required to destabilize existing bonds and initiate a chemical reaction.

Catalysts

Substances that lower activation energy without being consumed in the reaction.

Enzymes

Biological catalysts that speed up reactions by lowering activation energy.

Active Site

Region of an enzyme where substrate binding occurs, forming the enzyme-substrate complex.

Competitive Inhibitor

Substance that competes with the substrate for the active site of an enzyme.

Allosteric Enzymes

Enzymes that exist in active and inactive forms, regulated by allosteric sites.

Feedback Inhibition

Mechanism where an end product inhibits an earlier step in a metabolic pathway to prevent over-accumulation.

Gibbs Free Energy (G)

Energy available to do work, calculated as G = H - TS where H is enthalpy, T is absolute temperature, and S is entropy.

Metabolism

Total of all chemical reactions carried out by an organism; includes anabolic (building) and catabolic (breaking down) reactions.