A report on Cofactor (biochemistry) and Niacin

The succinate dehydrogenase complex showing several cofactors, including flavin, iron–sulfur centers, and heme.

A man with pellagra, which is caused by a chronic lack of vitamin B3 in the diet

A simple [Fe2S2] cluster containing two iron atoms and two sulfur atoms, coordinated by four protein cysteine residues.

Niacin, serotonin (5-hydroxytryptamine), and melatonin biosynthesis from tryptophan

The redox reactions of nicotinamide adenine dinucleotide.

Vitamins can serve as precursors to many organic cofactors (e.g., vitamins B1, B2, B6, B12, niacin, folic acid) or as coenzymes themselves (e.g., vitamin C).

- Cofactor (biochemistry)

Niacin and nicotinamide are both converted into the coenzyme NAD.

- Niacin

5 related topics with Alpha

Vitamin

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Organic molecule that is an essential micronutrient that an organism needs in small quantities for the proper functioning of its metabolism.

Calcium combined with vitamin D (as calciferol) supplement tablets with fillers.

Jack Drummond's single-paragraph article in 1920 which provided structure and nomenclature used today for vitamins

Some sources list fourteen vitamins, by including choline, but major health organizations list thirteen: vitamin A (as all-trans-retinol, all-trans-retinyl-esters, as well as all-trans-beta-carotene and other provitamin A carotenoids), vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B7 (biotin), vitamin B9 (folic acid or folate), vitamin B12 (cobalamins), vitamin C (ascorbic acid), vitamin D (calciferols), vitamin E (tocopherols and tocotrienols), and vitamin K (phylloquinone and menaquinones).

The B complex vitamins function as enzyme cofactors (coenzymes) or the precursors for them.

Riboflavin

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Vitamin found in food and sold as a dietary supplement.

Cultures of Micrococcus luteus growing on pyridine (left) and succinic acid (right). The pyridine culture has turned yellow from the accumulation of riboflavin.

It is essential to the formation of two major coenzymes, flavin mononucleotide and flavin adenine dinucleotide.

The coenzymes are also required for the metabolism of niacin, vitamin B6, and folate.

Nutrient

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Substance used by an organism to survive, grow, and reproduce.

Vitamins are organic compounds essential to the body. They usually act as coenzymes or cofactors for various proteins in the body.

Humans require thirteen vitamins in their diet, most of which are actually groups of related molecules (e.g. vitamin E includes tocopherols and tocotrienols): vitamins A, C, D, E, K, thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folate (B9), and cobalamin (B12).

Vitamin B6

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One of the B vitamins, and thus an essential nutrient.

Its active form, pyridoxal 5′-phosphate, serves as a coenzyme in more than 140 enzyme reactions in amino acid, glucose, and lipid metabolism.

5) PLP is required for the conversion of tryptophan to niacin, so low vitamin B6 status impairs this conversion.

Nicotinamide adenine dinucleotide

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Some metabolic pathways that synthesize and consume NAD in vertebrates. The abbreviations are defined in the text.

Salvage pathways use three precursors for NAD+.

Rossmann fold in part of the lactate dehydrogenase of Cryptosporidium parvum, showing NAD in red, beta sheets in yellow, and alpha helices in purple.

In this diagram, the hydride acceptor C4 carbon is shown at the top. When the nicotinamide ring lies in the plane of the page with the carboxy-amide to the right, as shown, the hydride donor lies either "above" or "below" the plane of the page. If "above" hydride transfer is class A, if "below" hydride transfer is class B.

A simplified outline of redox metabolism, showing how NAD and NADH link the citric acid cycle and oxidative phosphorylation.

Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism.

In organisms, NAD can be synthesized from simple building-blocks (de novo) from either tryptophan or aspartic acid, each a case of an amino acid; alternatively, more complex components of the coenzymes are taken up from nutritive compounds such as niacin; similar compounds are produced by reactions that break down the structure of NAD, providing a salvage pathway that “recycles” them back into their respective active form.