{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

The oxidation - mitochondria A gradient is formed when...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
The oxidation-reduction reactions performed by the coenzymes and other molecules are  essential to the energy metabolism of the cell. Other molecules participating in this  energy reaction are called cytochromes. Together with the enzymes, cytochromes  accept and release electrons in a system referred to as the electron transport system.  The passage of energy-rich electrons among cytochromes and coenzymes drains the  energy from the electrons. This is the energy used to form ATP from ADP and  phosphate ions.  The actual formation of ATP molecules requires a complex process referred to as  chemiosmosis. Chemiosmosis involves the creation of a steep proton gradient, which  occurs between the membrane-bound areas. In prokaryotic cells (for example, bacteria),  it is the area of the cell membrane; in eukaryotic cells, it is the membranes of the 
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: mitochondria. A gradient is formed when large numbers of protons (hydrogen ions) are pumped into membrane-bound compartments. The protons build up dramatically within the compartment, finally reaching an enormous number. The energy used to pump the protons is energy released from the electrons during the electron transport system. After large numbers of protons have gathered at one side of the membrane, they suddenly reverse their directions and move back across the membranes. The protons release their energy in this motion, and the energy is used by enzymes to unite ADP with phosphate ions to form ATP. The energy is trapped in the high-energy bond of ATP by this process, and the ATP molecules are made available to perform cell work....
View Full Document

{[ snackBarMessage ]}