Why do electrons carried by nadh

Krebs Cycle takes place in the mitochondrial matrix and requires oxygen. The ETC takes place in the mitochondrial matrix and requires oxygen.

Glucose : A simple, 6 carbon sugar that serves as the primary energy source in the body. ATP Adenosine triphosphate : The major energy currency of the cell. ATP is a high-energy molecule that stores and transports energy within cells. Glycolysis is the first of the three steps used to breakdown glucose to produce ATP. Glucose, a 6 carbon sugar, is split into two 3 carbon sugars.

The 3 carbon sugars are then oxidized and their remaining atoms reaarranged to form two molecules of pyruvate. Preparatory phase : Energy in glucose cannot be readily released unless energy from ATP if added first. In this phase, 2 ATP are added to the reaction, producing a glucose molecule with two phosphate groups. The phosphate groups make glucose less stable and ready for chemical breakdown. Payoff phase : Investment of energy in prepatory phase is paid back with interest!

The end product of Glycolysis, pyruvate, is transported into the mitochondrion and converted to a compound called acetyl coenzyme A or acetyl CoA. Mitochondrial respiration may occur without ATP production, as long as the released protons are able to return to the matrix without passing through the ATP synthetase.

This can happen e. In brown adipose tissue, a special protein thermogenin forms a proton channel in the mitochondion inner membrane. The flow of protons back into the matrix through this protein instead of ATP synthetase is responsible for the heat generation characteristic of this tissue. An excellent text. It presents Biochemistry with frequent references to organic chemistry and biochemical logic.

Highly reccommended for students of Biochemistry, Chemistry and Pharmaceutical Sciences. Biochemistry, Stryer A widely used classical text, frequently updated and re-issued. O 2 has a difficult time picking up one extra electron to form the free-radical species O 2 - ; however, once O 2 has accepted one electron it becomes very reactive, and can easily accept more electrons, or participate in other chemical reactions.

A free radical is a group that contains an unpaired electron. Free radicals are extremely reactive. Many of the chemical reactions that the free radical O 2 - could participate in, such as the destruction of fatty acids that make up membranes, would be very harmful to the body. Cytochrome oxidase acts as an enzyme to help add the first electron to O 2. However, recall that cytochrome oxidase can only transfer one electron at a time to oxygen, and that adding only one electron would result in a dangerous free radical.

Hence, the protein must have a mechanism to hold the oxygen in place until all four electrons have been transferred to O 2 i. Cytochrome oxidase contains a special bimetallic center consisting of a heme iron-containing group in close proximity to a copper atom.