Energy and Metabolism

Vocabulary flashcards based on key concepts in energy and metabolism.

Metabolic Pathway

A series of chemical reactions that takes a starting molecule and modifies it step-by-step through metabolic intermediates, yielding a final product.

Bioenergetics

The concept of energy flow through living systems, particularly how cells obtain and use energy.

First Law of Thermodynamics

The principle stating that energy in a closed system is conserved; it can be transformed but not created or destroyed.

Second Law of Thermodynamics

The principle stating that energy transfers increase entropy in a system; some energy becomes unavailable for work.

Kinetic Energy

The energy associated with objects in motion.

Potential Energy

The stored energy in an object or system due to its position or arrangement.

Endergonic Reaction

A chemical reaction that requires energy input and results in products that store more energy than the reactants.

Exergonic Reaction

A chemical reaction that releases energy and results in products that store less energy than the reactants.

Enzyme

A protein that acts as a catalyst in biochemical reactions, lowering the activation energy required.

Activation Energy

The initial energy required for a chemical reaction to occur.

Catalyst

A substance that increases the rate of a chemical reaction without being consumed in the process.

Feedback Inhibition

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

Chemiosmosis

The process of generating ATP by the movement of hydrogen ions across a membrane through ATP synthase.

Glycolysis

The metabolic pathway that breaks down glucose to form pyruvate, producing ATP and NADH in the process.

Citric Acid Cycle

A series of enzyme-catalyzed reactions that generate energy through the oxidation of acetyl CoA derived from carbohydrates, fats, and proteins.

Oxidative Phosphorylation

The final stage of cellular respiration where ATP is produced through the use of the electron transport chain and chemiosmosis.

Fermentation

A metabolic process that regenerates NAD+ from NADH in the absence of oxygen, allowing glycolysis to continue.

ATP (Adenosine Triphosphate)

The primary energy currency of the cell, used to power various energy-requiring processes.

Allosteric Inhibition

A form of enzyme regulation where an inhibitor binds to a site other than the active site, causing a conformational change that reduces enzymatic activity.

Cofactor

An inorganic ion required for an enzyme's activity.

Coenzyme

An organic molecule that assists enzymes in catalysis, often derived from vitamins.

Substrate

The specific reactant that an enzyme acts upon in a biochemical reaction.