Oxidative phosphorylation is a fundamental process occurring within all animal cells that produces the majority of ATP, the cell's primary energy source, and takes place within the mitochondria. The process of oxidative phosphorylation involves two main components: the electron transport chain (ETC) and ATP synthase. It begins with the breakdown of glucose and other nutrient molecules through glycolysis and the citric acid cycle, leading to the production of reducing agents, such as nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FADH2). These two reducing agents carry high-energy electrons that are then used to generate ATP. The ETC is located within the inner mitochondrial membrane and consists of four main protein complexes (I to IV) and two mobile electron carriers: ubiquinone (Q) and cytochrome c. NADH and FADH2 donate their electrons to complex I and complex II, respectively. These electrons are then shuttled through the ETC from one complex to another, losing energy in the process. The energy released is used to pump protons (H+) from within the mitochondrial matrix into the intermembrane space, creating an electrochemical gradient. Complex I (NADH dehydrogenase) accept electrons from NADH and transfers them to ubiquinone (Q), which becomes reduced (QH2). Simultaneously, protons are pumped across the inner mitochondrial membrane, contributing to the proton gradient. Complex II (succinate dehydrogenase) receives electrons from FADH2 and transfers them to ubiquinone (Q), producing QH2. Though complex II does not directly pump protons, it feeds electrons into the ETC to maintain the proton gradient. In the ETC ubiquinone (QH2) acts as a mobile electron carrier, diffusing within the inner mitochondrial membrane and delivering electrons to complex III (cytochrome bc1 complex). Here, cytochrome c, another mobile electron carrier located in the intermembrane space, is reduced. Electrons continue to move through the ETC to complex IV (cytochrome c oxidase), where they are finally transferred to molecular oxygen (O2), reducing it to water (H2O). During electron transfer through complexes I, III, and IV, protons are pumped from within the mitochondrial matrix into the intermembrane space. This creates a proton gradient, generating a proton motive force utilized by the final component of oxidative phosphorylation, ATP synthase (complex V). ATP synthase is embedded in the inner mitochondrial membrane and allows protons to flow back into the mitochondrial matrix down their concentration gradient, coupling their movement to the synthesis of ATP from adenosine diphosphate (ADP) and inorganic phosphate (Pi). ATP synthase consists of two subunits, F0 and F1. The F0 subunit forms the transmembrane channel allowing protons to pass through, driving the physical rotation of the F1 subunit inside the matrix. This rotation enables ATP synthase to efficiently catalyse the synthesis of ATP from ADP and Pi. Oxidative phosphorylation is therefore highly efficient, with each NADH molecule leading to the synthesis of about three ATP molecules, and each FADH2 molecule contributing to the production of about two ATP molecules. Thus, oxidative phosphorylation is a fundamental and essential process in energy production in animal cells, producing the energy required for many cellular functions. We offer a wide product range of research reagents for investigating oxidative phosphorylation, including Cytochrome C antibodies, SDHB antibodies, ATP5A antibodies, NDUFB9 antibodies, and Ndufs1 antibodies. Explore our full oxidative phosphorylation product range below and discover more, for less. Alternatively, you can explore our Complex I, Complex IV, and Complex II product ranges.