The most prevalent and efficient catabolic pathway, in which oxygen is consumed as a reactant along with the organic fuel (aerobic from the Greek aer, air, and bios, life).

The cells of most eukaryotic and many prokaryotic organisms can carry out aerobic respiration.

Some prokaryotes use substances other than oxygen as reactants in a similar process that harvests chemical energy without usuing any oxygen at all; this process is called anaerobic respiration (the prefix an- means "without").

Includes both aerobic and anaerobic processes.

Originated as a synonym for aerobic respiration because of the relationship of that process to organismal respiration, in which an animal breathes in oxygen. Thus, cellular respiration is often used to refer to the aerobic process.

Also known as an oxidation-reduction reaction.

In many chemical reactions, there is a transfer of one or more electrons (e-) from noe reactant to another. 

The loss of electrons from one substance in a redox reaction.

Also called the "reducing agent" as it reduces the other substance which gains the lost electron.

The addition of electrons to another substance in redox reactions.

Also called the oxidizing agent as it gained the electron which was lost by the other substance. Oxidizing the other substance it is paired with.

Nicotinamide Adenine Dinucleotide

A coenzyme which is a popular electron carrier within mitochondria cellular respiration.

Functions as an oxidizing agent.

When electrons are gained NAD+ becomes NADH.

Used in cellular respiration to harvest electrons and energy from the breakdown of glucose.

Meant to break the fall of electrons to oxygen into several energy-releasing steps. An electron transport chain consists of a number of one carrier molecule t the next in a series of redox reactions, losing a small amount of energy with each step until they finally reach oxygen, the terminal electron acceptor, which has a very great affinity for electrons. 

Each "downhill" carrier is more electronegative than, and thus capable of oxidizing, it's "uphill" neighbor, with oxygen at the bottom of the chain.

The first stage of cellular respiration with catabolic pathways that break down glucose and other organic fuels.

Glycolysis, which occurs in the cytosol, begins the degradation process by breaking glucose into two molecules of a compound called pyruvate.

The second stage of cellular respiration with catabolic pathways that break down glucose and other organic fuels.

The citric acid cycle which takes place in the mitochonrian matrix of eukaryotic cells or simply in the cytosol of prokaryotes, completes the breakdown of glucose by oxidizing a derivitive of pyruvate to carbon dioxide. Thsu, the carbon dioxide produced by respiration represents fragments of oxidized organic molecules.

A mode of ATP synthesis which is powered by the redox reactions of the electron transport chain.

Ie: At the end of the electron transport chain when the electrons are carried within H2O, and whenever NAD+ becomes NADH.

The process in which a smaller amount of ATP is formed directly in a few reactions of glycolysis and the citric acid cycle.

90% of ATP generated through oxidative phosphorylation, the rest is through substrate-level phosphorylation.

This mode of ATP synthesis occurs when an enzyme transfers a phosphate group from a substrate molecule to ADP, rather than adding an inorganic phosphate to ADP as in oxidative phosphorylation. 

Pyruvate is converted to Acetyl CoA when first entering the mitochondrion via active transport.

Acetyl CoA then enters the citric acid cycle.

Most of the remaining electron carriers between ubiquinone and oxygen are proteins called cytochromes. Their prosthetic group, called a heme group,has an iron atom that accepts and donates electrons.

The electron transport chain has several types of cytochromes, each a different protein with a slightly different electron-carrying heme group. 

The last cytochrome of the chain, cyt a3, passes its electrons to oxygen which is very electronegative.

Populate the inner membrane of the mitochondrion or the prokaryotic plasma membrane with many copies it's protein.

ATP Synthase is the enzyme that actually makes ATP from ADP and inorganic phosphate. 

Works like an ion pump running in reverse. 

Relies of the difference in the concentration of H+ on opposite sides of the inner mitochondrial membrane (Can also be thought of as a difference of pH).

A process in which energy stored in the form of a hydrogen ion gradient across a membrane is used to drive celular work such as the synthesis of ATP.

 (As in the Greek 'osmos' push)

Osmosis refers to water transport, however chemiosmosis is the flow of H+ across a membrane.

Pyruvate is converted to ethanol in two steps.

The first step releases carbon dioxide from the pyruvate, which is converted to the two-carbon compound acetaldehyde. 

In the second step, acetaldehyde is reduced by NADH to ethanol. This re-generates the supply of NAD+ needed for the continuation of glycolysis. 

The species of Obligate anaerobes.

In such cells, pyruvate is a fork in the metabolic road that leads to two alternative catabolic routes. Under aerobic conditions, pyruvate can be converted to acetyl CoA, and oxidation continues in the citric acid cycle. Under anaerobic conditions pyruvate is diverted from the citric acid cycle, serving instead as an electron acceptor to recycle NAD+.

To make the same amount of ATP, a facultative anaerobe would have to consume sugar at a much faster rate when fermenting than when respiring.