Concept
Organic substances are decomposed to decompose carbon dioxide, water in biological cells, and release a large amount of energy, refer to Biolog oxidation, also known as cell breathing or tissue. breathe.
Features
Biooxidation and organic matter body outside the combustion in chemistry is essentially the same, follow the general law of redox reaction, the amount of oxygen, the final product, and the release of energy All are the same.
(1) is an oxidation process in which the enzyme catalyzed oxidation process is performed, and the reaction conditions are mild (pH in the aqueous solution of about 7 and normal temperature).
(2) In the process of biocioxidation, the production of the biological reduction reaction is accompanied.
(3) Water is a morally oxidation reaction of many bio-oxidation reactions, directly involved in oxidation reactions by water dehydrogenation.
(4) In bio oxidation, oxidation and hydrogenation of carbon are non-synchronous. The protons and electrons from the oxidation process are typically transmitted by various carriers, such as NADH, and the like, and finally generate water.
(5) Bio oxidation is a step-by-step process. Each step has a special enzyme catalysis, and the product of each step can be separated. This step-by-step model is advantageous to release energy under gentle conditions and increase energy utilization.
(6) The energy released by bio-oxidation, by conforming to the ATP synthesis, converted into a biological energy ATP that can be directly utilized.
Part
In eukaryotic biological cells, biocioxidation is mainly carried out in the mitochondria, and the prokaryotic organism is carried out on the cell membrane.
The system belonging
Enzyme
is important for both oxidase and dehydrogenase, especially the dehydrogenase is especially important.
Oxidase is a copper-containing or iron protein, activates molecular oxygen, promotes direct oxygenation of oxygen to metabolites, can only be used as hydrogen by oxygen, producing water. Important cytochrome oxide enzymes can reduce the reduction type into oxidation type, and hydrogen-discharged electrons can be transmitted to molecular oxygen so that it is activated. There are many in myocardial content. In addition, there is an oxide enzyme, a hydrogenide, and the like.
Dehydrogenase divided oxyhydridase and no oxygen dehydrogenase. The former can activate hydrogen in the metabolic molecule, bind to molecular oxygen, producing hydrogen peroxide. Mild blue is hydrogen in a non-molecular oxygen. The oxygen dehydrogenase is a coenzyme in FMN or FAD. No oxygen dehydrogenase can activate hydrogen in metabolic molecules to transfer the extravasive hydrogen to the hydrogen or non-molecular oxygen. Metabolic oxidation is generally promoted in an oxygen or hypoxic environment. Most of them are coenzymes with NAD or NADP.
system
There are two systems that do not need to transmit body and need to be transmitted.
Does not need to transmit the simplest, the metabolite, peroxidase, and hydrogen peroxidase or oxygen molecular oxygen generated water or overdone Hydrogen peroxide. It is characterized by free from phosphorylation and does not generate ATP, mainly related to biological conversion of metabolites, drugs and toxicities in vivo.
The most typical behavior of the bodies is the breathing chain. It is the catalysis of the mitochondrial through the polysetal system, i.e., the completion of the electronic transmission chain, is related to the generation of ATP.
Oxidation was generated in
Biooxidation of CO2 is caused by the decarboxylation reaction of organic acid in metabolism. There are two types of direct decarboxylation and oxidative donation. The α-decarboxylation and β-decarboxylation are in the position of the decarboxylate.
Oxidation
Sugar metabolism The tricarboxylic acid cycle and fatty acid β-oxidation is to generate NADH (reductive equivalents) in mitochondria, and can immediately extract an electronically phosphorylated . NADH produced in the cytosol of the cells, such as glycolysis, which causes the hydrogen of NADH into the mitochondrial inline oxidation by shuttle system.
(1) α-phosphoric acid flowing
This role is mainly in the brain, skeletal muscle, and the carrier is alpha-phospholiourne.
The NADH in the cyclosol is reduced to α-phosphate hydroxyacetone as an alpha-phosphate, the latter, and the latter is passed by the inner mitochondria - Glycerol dehydrogenase (auxiliary group) catalyzed to regenerate dihydroxyacetone and FadH2, the latter enters the succinate oxidation breathing chain to generate 1.5 molecule ATP. Glucose thoroughly oxidize the ATP in these tissues than other tissue, 1 mole g → 30 molar ATP.
(b) Meric-aspartate shuttle effect
NADH in the cyclosolifier is reduced to malic acid under the dehydrogenase of malic acid, after Based on the α-ketoctate vector on the endometrium into the mitochondria, grassyl acetic acid and NADH were re-formed under the catalysis of the dehydrogenase in the mitochondria. NADH enters the NADH oxidation breathing chain to generate 2.5 molecules ATP. Ethylene acetic acid is catalyzed by vitamin transaminase to form aspartic acid, and the latter is then transferred through the acidic amino acid carrier to transit into oxalacetate.
Related Factors
(1) Inhibitor
The substance that can block a part of the breathing chain is referred to as a breathing chain inhibitor.
Tomorous ketones, inhibited electron transfer at NADH dehydrogenses, block NADH oxidation, but FadH2 oxidation can still be carried out.
Treatment of mymp A inhibiting the transfer of electrons in cytochrome BC1 composites.
Cyanide, CO, azide (N3-) inhibits cytochrome oxidase.
The substance of electron transmission and ADP phosphorylation is suppressed, called an inhibitory inhibitor such as an oligomycin.
(b) Decuting agent
2,4-dinitrophenol (DNP) and determination of oxidation and phosphorylated coupling process, Transfer as usual without generating an ATP. The action mechanism of DNP is to transport it into the inside of the mitochondria as an H + carrier to form a proton gradient. The energy generated by electron transfer is released by heat.
(3) Adjustment of ADP
The rate of nationrification of normal body is mainly adjusted by ADP levels, only ADP is phosphorylated to form ATP, and electrons flow through the breathing chain flow to oxygen . If ADP is supplied, with the concentration of ADP, electronic transmission is carried out, and ATP is synthesized, but the electron transfer slows down with the decrease in the concentration of ADP. This process is called breathing control, which ensures that the electronic flow occurs only when the ATP synthesis is required.