Chapter 7: Cellular Respiration and Fermentation Vocab

Proton-motive force

The potential energy stored in the form of a protein electrochemical gradient, generated by the pumping of hydrogen ions (H+) across a biological membrane during chemiosmosis.

Oxidation

The complete or partial loss of electrons from a substance involved in a redox reaction.

ATP synthase

A complex of several membrane proteins that functions in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion (proton) concentration gradient to make ATP. They are found in the inner mitochondrial membranes of eukaryotic cells and in the plasma membranes of prokaryotes.

Alcohol fermentation

Glycolysis followed by the reduction of pyruvate to ethyl alcohol, regenerating NAD+ and releasing carbon dioxide.

Oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.

Glycolysis

A series of reactions that ultimately splits glucose into pyruvate. It occurs in almost all living cells, serving as the starting point for fermentation or cellular respiration

NADH

The reduced form of nicotinamide adenine dinucleotide , which temporarily stores electrons during cellular respiration. It acts as an electron donor to the electron.

Facultative anaerobe

An organism that makes ATP by aerobic respiration if oxygen is present but that switches to anaerobic respiration or fermentation if oxygen is not present.

Electron transport chain

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons down a series of redox reactions that release energy used to make ATP.

Chemiosmosis

An energy coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a such as the synthesis of ATP. Under aerobic conditions, most ATP synthesis in cells occurs by chemiosmosis.

Beta oxidation

A metabolic sequence that breaks fatty acids down to 2-carbon fragments that enter the citric acid cycle as acetyl CoA.

Citric acid cycle

A chemical cycle involving 8 steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl CoA ( derived from pyruvate) to carbon dioxide; occurs within the mitochondrion in eukaryotic cells and in the cytosol of prokaryotes; together with pyruvate oxidation, the second major stage in cellular respiration.

Fermentation

A catabolic process that makes a limited amount of ATP from glucose (or other organic molecules) without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid.

Substrate level phosphorylation

The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.

Reduction

The complete or partial addition of electrons to a substance involved in a redox reaction.

Cellular respiration

The catabolic pathways of aerobic and anaerobic respiration, which break down organic molecules and use an electron transport chain for the production of ATP

Oxidizing agent

The electron acceptor in a redox reaction

Lactic acid fermentation

Glycolysis followed by the reduction of pyruvate to lactate, regenerating NAD+ with no release of carbon dioxide.

Cytochrome

An iron containing protein that is a component of an electron that is a component of electron transport chains in the mitochondria and chloroplasts of eukaryotic cells and the plasma membranes of prokaryotic cells.

Aerobic respiration

A catabolic pathway for organic molecules , using oxygen as the final electron acceptor in an electron transport chain and ultimately producing ATP. This is the most efficient catabolic pathway and is carried out in most eukaryotic cells and many prokaryotic organisms

Obligate anaerobe

An organism that only carries out fermentation or anaerobic respiration. Such organisms cannot use oxygen and in fact may be poisoned by it.

Redox reaction

A chemical reaction involving the complete or partial transfer of one or more electrons from one reactant to another; short for reduction

Reducing agent

The electron donor in a redox reaction

NAD+

The oxidized form of nicotinamide adenine dinucleotide, a coenzyme that can accept electrons becoming NADH. NADH temporarily stores electrons during cellular respiration.

Acetyl CoA

Acetyl coenzyme A; the entry compound for the citric acid cycle in cellular respiration, formed from a 2