Ch. 4 Chapter Summary - Concepts of Biology

Flashcards covering the key vocabulary and concepts of metabolism, energy transformation, glycolysis, and oxidative phosphorylation from the Concepts of Biology summary.

Metabolism

The combination of chemical reactions that take place within a cell.

Catabolic reactions

Chemical reactions that break down complex chemicals into simpler ones and are associated with energy release.

Anabolic processes

Chemical reactions that build complex molecules out of simpler ones and require energy.

System

The matter and environment involved in energy transfers.

Entropy

A measure of the disorder of a system.

Laws of thermodynamics

The physical laws that describe the transfer of energy.

First law of thermodynamics

The law stating that the total amount of energy in the universe is constant.

Second law of thermodynamics

The law stating that every energy transfer involves some loss of energy in an unusable form, such as heat energy.

Exergonic

A reaction where the change in free energy is negative, thus releasing energy.

Endergonic

A reaction where the change in free energy is positive, thus consuming energy.

Activation energy

The initial input of energy required for all chemical reactions to proceed.

Enzymes

Chemical catalysts that speed up chemical reactions by lowering their activation energy.

Active site

A unique chemical environment on an enzyme that fits particular chemical reactants.

Substrates

The particular chemical reactants that bind to an enzyme's active site.

Induced-fit model

The model describing the binding process between enzymes and substrates.

ATP

The energy currency for cells that facilitates brief energy storage and transport to support endergonic reactions; its structure is an RNA nucleotide with $3$ phosphate groups.

ADP

The product formed when a phosphate group is detached from ATP during the release of energy.

Glycolysis

The first pathway used in the breakdown of glucose to extract energy, resulting in a net gain of $2$ ATP per molecule of glucose.

Citric acid cycle

A series of chemical reactions that removes high-energy electrons and uses them in the electron transport chain to generate ATP.

Electron transport chain

The portion of aerobic respiration that uses free oxygen as the final electron acceptor for electrons removed from intermediate compounds.

Chemiosmosis

A process in which a gradient of hydrogen ions transported across a membrane is used to generate ATP.

Fermentation

A process used to regenerate $NAD^+$ from $NADH$ in the absence of aerobic respiration, ensuring the continuation of glycolysis.