Each  produces 3  molecules in the electron transport chain while each  produces 2  molecules. Each glucose molecule results in the formation of 10  molecules, which go on to produce 30 . Each glucose molecule results in the formation of 2  molecules, which go on to produce 4 . Note that some references may indicate that each  produces 2.5 , while each  produces 1.5 . These are theoretical maximums and depend on the organism, cell type, and cellular environment.

A total of 38 ATP molecules are produced from one molecule of glucose. 2 ATP from glycolysis, 2 ATP from the Krebs cycle, and about 34 ATP from the electron transport chain. Note that this is a theoretical maximum and is rarely seen in nature.

In electron transport, the energy that is released as electrons flow down a potential energy gradient is coupled to the movement of protons from the mitochondrial matrix across the inner mitochondrial membrane into the intermembrane space. This direction of flow is against the protons' concentration gradient and thus requires energy, which is provided by the spontaneous passage of electron down a potential energy gradient of enzyme complexes.

 are the two electron carriers in the Krebs cycle. ATP is the energy compound that is created in respiration. Carbon dioxide is a waste product from the Krebs cycle.  Nitrogen is not involved in the Krebs cycle. Oxygen is an electron acceptor, and hydrogen is added to the electron carriers.

The concentration gradient of protons feeds into ATP synthase structure, which creates ATP. Water does not feed into ATP synthase. ADP does not accept the hydrogen to create ATP, rather it is the substrate onto which a phosphate group is added to create ATP. NADH gives up a hydrogen in the electron transport chain to create the concentration gradient. It does not pass through ATP synthase.

The mitochondrion is composed of an outer membrane, matrix, inner membrane and inner membrane space. The components of the electron transport chain, namely the cytochrome proteins and ATP synthase, are arranged on the inner membrane to allow for the movement of protons between the inner membrane space and matrix in order to create ATP.

The final electron acceptor of the electron transport chain in cellular respiration is oxygen. Additionally carbon dioxide is produced as a waste product during the citric acid cycle phase of cellular respiration.

A reducing agent works as an electron donor, so it is ultimately giving away electrons to another molecule and ultimately making that other molecule more negative in charge, or reduced in charge. Note that a reducing agent is itself oxidized. Also recall the mnemonic OIL RIG (Oxidation Is Loss of electrons, Reduction Is Gain of electrons).

Cellular respiration begins with the process of breathing in oxygen and consuming glucose. Through a series of reactions they eventually produce energy in the form of  and heat, as well as byproducts such as , which is exhaled, and water molecules.

Glucose is the primary molecule that heterotrophs use to make energy at a cellular level. Heterotrophs use glucose for a starting material in both fermentation and cellular respiration. However fermentation is performed without oxygen (anaerobic), while cellular respiration requires oxygen as a final electron receptor at the end of the electron transport chain.