Features: Enzyme catalysis is required, and it is completed step by step.

Microsomal oxidation system: The oxidation reactions that occur in microsomes, endoplasmic reticulum, etc. are mainly oxidative modification and transformation of substrates, without the generation of ATP.

Features: The reaction is mild, requires enzymes, and requires a variety of components capable of transferring hydrogen and electrons to participate in the redox reaction.

Nicotinamide adenine nucleotides transport hydrogen and electricity.

Flavin nucleotide derivatives transfer hydrogen and electrons

The organic compound ubiquinone transports hydrogen and electrons.

Iron-sulfur proteins and cytochrome proteins transport electrons

respiratory chain

Complex I transfers electrons from NADH to ubiquinone

Complex II transfers electrons from succinate to ubiquinone.

Complex III transfers electrons from reduced ubiquinone to cytochrome c

Complex IV transfers electrons from cytochrome c to oxygen

A chain called NADH, with NADH as the electron donor, starts from NAFH and reduces oxygen to generate water: NADH→Complex I→Q→Complex III→Cytc→Complex IV→Q2

The other is called the FADH2 respiratory chain, also called the succinic acid oxidation respiratory chain. FADH2 is used as an electron donor and passes through complex II to oxygen to generate water: succinic acid → complex II → Q → complex III → Cytc → complex IV→O2

One is coupled with a high-energy bond hydrolysis reaction to directly transfer the energy of high-energy metabolites to ADP to generate ATP. This process is called substrate-level phosphorylation.

90% of ATP in the human body is produced by oxidative phosphorylation in mitochondria

P/O

The two key processes are: one is electron transfer, and the other is using the energy released during the electron transfer process to generate ATP, so that the energy can be stored through ATP for use by the body.

free energy change

The proton concentration, positive charge on the cytoplasmic side of the mitochondria is much higher than the mechanism.

ATP and enzymes are mushroom-like structures composed of multi-proteins, containing F1 (the hydrophilic part F1 represents the first identified factor related to oxidative phosphorylation.) and F0 (the hydrophobic part, F0 represents oligomycin sensitivity.) functional domain.

F1 mainly consists of α3, 3β, γδε subunit complex and oligomycin-sensitive protein.

You are composed of hydrophobic a, b2, c9~12 subunits in the inner mitochondrial membrane, forming a proton channel across the inner membrane.

The ATP synthase rotor circulates once to generate three molecules of ATP.

Features

ATP is an important molecule for energy capture and release utilization

ATP is central to energy transfer and the interconversion of nucleotides.

ATP provides energy by transferring its own radicals.

Creatine phosphate is also a high-energy compound that stores energy

The role of ATP synthase: The proton driving force generated by the electron transfer of ATP synthase in the inner mitochondrial membrane promotes the return of protons through the ion channel of ATP synthase, and the released energy is used to generate ATP.

There is a single electron transfer process in the mitochondrial respiratory chain.

Mechanism: One oxygen atom in the catalytic oxygen molecule is added to the substrate molecule for strengthening, and the other oxygen atom is reduced to water by NADPH H.

Cytochrome P450 monooxygenase is also called mixed function oxidase or hydroxylase.

Function

Monooxygenases are most abundant in microsomes of the liver and adrenal glands and are the most complex enzymes with hundreds of isoenzymes.

Reactive oxygen species: oxygen-containing molecules that have not been completely reduced and are much more oxidizing than oxygen

The mitochondrial respiratory chain is the main step in producing ROS.

Catalase mainly exists in peroxisomes, and cytoplasmic microsomes contain 4 heme prosthetic groups. It has strong catalytic activity and can catalyze the conversion of more than 40,000 substrate molecules into products per second.

Glutathione peroxidase is also an indispensable enzyme in the body to prevent ROS damage.

Other small molecule free radical scavengers in the body include vitamin C, vitamin E, β-carotene, etc., which together with the antioxidant enzymes in the body form the human body’s antioxidant system.

The body regulates ATP synthesis by regulating the rate of oxidative phosphorylation according to its own energy needs.

The concentration of ATP in cells and the ratio of ATP/ADP can quickly sense changes in the body's energy status.

The relative concentrations of ATP and ADP also regulate glycolysis and the tricarboxylic acid cycle pathway to meet the needs of oxidative phosphorylation for NADH and FADH2.

Inhibitors block any link in the electron transport chain or inhibit the phosphorylation process of ADP

Respiratory chain inhibitors block the electron transport process.

Uncoupling agents block the phosphorylation process of ADP.

ATP synthase inhibitors inhibit both electron transport and ATP production

Functional proteins of mitochondria are mainly encoded by genes in the nucleus.

Hereditary mt DNA diseases are mostly maternally inherited

The outer membrane has high permeability to substances and low selectivity: it mainly depends on the transport of various substances by different transport proteins in the inner membrane.

NADH in the cytoplasm enters the mitochondrial respiratory chain through a shuttle mechanism

ATP-ADP translocase coordinates the transport of ADP and ATP into and out of mitochondria