Cellular respiration is the process of extracting energy in the form of ATP from the glucose in the food you eat. In stage one, glucose is broken down in the cytoplasm of the cell in a process called glycolysis. In stage two, the pyruvate molecules are transported into the mitochondria.

Photosynthesis makes the glucose that is used in cellular respiration to make ATP. While photosynthesis requires carbon dioxide and releases oxygen, cellular respiration requires oxygen and releases carbon dioxide. It is the released oxygen that is used by us and most other organisms for cellular respiration.

During cellular respiration, a glucose molecule is gradually broken down into carbon dioxide and water. Along the way, some ATP is produced directly in the reactions that transform glucose. Much more ATP, however, is produced later in a process called oxidative phosphorylation.

Cellular respiration occurs in three stages: glycolysis, the Krebs cycle, and electron transport.

The second stage takes place in the mitochondria. There, the small molecules are broken down even more. This change requires oxygen and releases a great deal of energy that the cell can use for all its activities. No wonder mitochondria are sometimes called the “powerhouses of the cell!

The primary task of the last stage of cellular respiration, the electron transport chain, is to transfer energy from the electron carriers to even more ATP molecules, the “batteries” which power work within the cell.

What is the purpose of the ETC? The main purpose of the electron transport chain is to build up a surplus of hydrogen ions (protons) in the intermembrane space sp that there will be a concentration gradient compared to the matrix of the mitochondria. This will drive ATP synthase.

mitochondria

The electron transport chain (ETC) is the major consumer of O2 in mammalian cells. The ETC passes electrons from NADH and FADH2 to protein complexes and mobile electron carriers. Coenzyme Q (CoQ) and cytochrome c (Cyt c) are mobile electron carriers in the ETC, and O2 is the final electron recipient.

Steps of the ETC The electron transport chain occurs across the inner mitochondrial membrane. Its main function is to build an electrochemical gradient across the inner membrane using protons. The ETC pumps hydrogen ions out of the matrix of the mitochondria and into the intermembrane space.

Electron transport helps establish a proton gradient that powers ATP production and also stores energy in the reduced coenzyme NADPH. This energy is used to power the Calvin Cycle to produce sugar and other carbohydrates.

The electron transport chain (aka ETC) is a process in which the NADH and [FADH2] produced during glycolysis, β-oxidation, and other catabolic processes are oxidized thus releasing energy in the form of ATP. The mechanism by which ATP is formed in the ETC is called chemiosmotic phosphorolation.

In fact, if electron transport is blocked the chemiosmotic gradient cannot be maintained. An inhibitor may competely block electron transport by irreversibly binding to a binding site. For example, cyanide binds cytochrome oxidase so as to prevent the binding of oxygen. Electron transport is reduced to zero.

The events of the electron transport chain involve NADH and FADH, which act as electron transporters as they flow through the inner membrane space. In complex I, electrons are passed from NADH to the electron transport chain, where they flow through the remaining complexes. NADH is oxidized to NAD in this process.

: any of several intracellular hemoprotein respiratory pigments that are enzymes functioning in electron transport as carriers of electrons.

four types

The term “P450” is derived from the spectrophotometric peak at the wavelength of the absorption maximum of the enzyme (450 nm) when it is in the reduced state and complexed with carbon monoxide. Most CYPs require a protein partner to deliver one or more electrons to reduce the iron (and eventually molecular oxygen).

Cytochrome P450 enzymes are essential for the metabolism of many medications. Cytochrome P450 enzymes can be inhibited or induced by drugs, resulting in clinically significant drug-drug interactions that can cause unanticipated adverse reactions or therapeutic failures.

There are 18 mammalian cytochrome P450 (CYP) families, which encode 57 genes in the human genome. CYP2, CYP3 and CYP4 families contain far more genes than the other 15 families; these three families are also the ones that are dramatically larger in rodent genomes.

Duke Of Earl 14:30, 3 March 2006 (UTC) From the reference reading listed (Nelson D.), it says the ‘P’ of Cytochrome P450 comes from ‘pigment’ but not ‘peak’.

liver cells

Among the drugs metabolized are sedatives such as midazolam, triazolam and diazepam, the antidepressives amitriptyline and imipramine, the anti-arryhthmics amiodarone, quinidine, propafenone and disopyramide, the antihistamines terfenadine, astemizole and loratidine, calcium channel antagonists such as diltiazem and …

Phase 1 metabolism involves chemical reactions such as oxidation (most common), reduction and hydrolysis. There are three possible results of phase 1 metabolism. The drug becomes completely inactive. One or more of the metabolites are pharmacologically active, but less so than the original drug.

Phase I reactions of drug metabolism involve oxidation, reduction, or hydrolysis of the parent drug, resulting in its conversion to a more polar molecule. Phase II reactions involve conjugation by coupling the drug or its metabolites to another molecule, such as glucuronidation, acylation, sulfate, or glicine.

The enzymes involved in Phase I reactions are primarily located in the endoplasmic reticulum of the liver cell, they are called microsomal enzymes. Phase II metabolism involves the introduction of a hydrophilic endogenous species, such as glucuronic acid or sulfate, to the drug molecule.