Oxidative Phosphorylation and Chemiosmosis

A set of flashcards covering key vocabulary and concepts related to oxidative phosphorylation, chemiosmosis, and cellular respiration.

Oxidative Phosphorylation

The metabolic process where ATP is formed as electrons are transferred to oxygen through the electron transport chain.

Chemiosmosis

The movement of ions across a selectively permeable membrane, which in ATP synthesis refers to the flow of protons (H+) through ATP synthase.

Electron Transport Chain

A series of protein complexes and other molecules that transfer electrons through redox reactions to produce ATP.

NADH

A reduced coenzyme that carries electrons to the electron transport chain, generated in glycolysis and the citric acid cycle.

ATP Synthase

An enzyme that synthesizes ATP from ADP and inorganic phosphate using the energy of a proton gradient.

Proton-Motive Force

The gradient of protons (H+) across a membrane that drives ATP synthesis during chemiosmosis.

Substrate-Level Phosphorylation

A method of ATP production that occurs by direct transfer of a phosphate group to ADP.

Cristae

The infoldings of the inner mitochondrial membrane that increase surface area for the electron transport chain.

Prosthetic Groups

Non-protein components that assist enzymes in catalyzing reactions, often found bound to enzymes.

Flavin Mononucleotide (FMN)

A prosthetic group used by enzymes in the electron transport chain, particularly in complex I.

Iron-Sulfur Proteins

Proteins that contain iron and sulfur, serving as electron carriers in the electron transport chain.

Ubiquinone

A lipid-soluble electron carrier in the electron transport chain, also known as coenzyme Q.

Cytochromes

Proteins that contain heme groups and function as electron carriers in the electron transport chain.

Heme Group

An iron-containing compound that binds to oxygen, found in hemoglobin and cytochromes.

Terminal Electron Acceptor

The final electron acceptor in the electron transport chain, typically oxygen in aerobic respiration.

Mitochondrial Matrix

The innermost compartment of the mitochondria where the citric acid cycle takes place.

Intermembrane Space

The space between the inner and outer membranes of the mitochondria where protons are pumped during electron transport.

ATP Yield

The total amount of ATP produced from one molecule of glucose during cellular respiration.

Aerobic Respiration

Respiration that requires oxygen to produce ATP.

Anaerobic Respiration

Respiration that occurs without oxygen and produces less ATP.

Chemiosmotic Mechanism

The process by which ATP is synthesized using the energy of a hydrogen ion gradient.

Redox Reactions

Chemical reactions involving the transfer of electrons from one molecule to another.

Metabolic Pathway

A series of biochemical reactions that lead to the transformation of a single type of substrate into a final product.

Citric Acid Cycle

A key metabolic pathway that oxidizes nutrients to produce energy carriers like NADH and FADH2.

Bioenergetics

The study of the transformation of energy in living systems.

Protons (H+)

Hydrogen ions that generate electrochemical gradients in biological membranes.

NAD+

The oxidized form of NADH, which serves as an electron acceptor in metabolic reactions.

FADH2

A reduced coenzyme similar to NADH, contributing to the electron transport chain.

Energy Conversion Efficiency

The ratio of useful energy output to the total energy input during a metabolic process.

Heat Production

The generation of heat as a by-product of metabolism.

Brown Fat

A specialized type of fat tissue that generates heat by dissipating the proton-motive force without producing ATP.

Endocrine System

The system of glands that secrete hormones regulating metabolism, growth, and other bodily functions.

Molecular Rotary Motor

A molecular structure like ATP synthase that rotates to perform mechanical work at the molecular level.

Electron Shuttle Systems

Mechanisms that transport electrons from glycolysis into the mitochondrion.

Hydrophobic Molecule

A molecule that does not interact well with water, such as ubiquinone.

Flow of Electrons

The movement of electrons through the electron transport chain, facilitating ATP production.

Concentration Gradient

A difference in concentration of a substance across a space, which drives molecular movement.

Enzymatic Function

The activity of an enzyme in catalyzing chemical reactions.

Feedback Inhibition

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

Phosphorylation

The addition of a phosphate group to a molecule, often changing its activity.

Habitual Temperature Regulation

The biological mechanism by which organisms maintain their body temperature.

Acceptance of Electrons

The process by which molecules, particularly in the electron transport chain, gain electrons.

Decoupling Proteins

Proteins that dissipate proton gradients without producing ATP.

Energy Harvesting

The process of converting energy from nutrients into usable cellular energy such as ATP.

Hypothesis Testing

A scientific method for determining the validity of a hypothesis through experiment and observation.

Fluid Membrane

A property of biological membranes allowing for the proper functioning of cellular processes.

Oxygen Reduction

The process where oxygen accepts electrons at the end of the electron transport chain.