Master Vitamin B6 (Pyridoxine) with Picmonic for Medicine

Transamination refers to a reaction between an amino acid, which contains an amine (NH2) group and a keto acid, which contains a keto (=O) group. In this reaction, the NH2 group on one molecule is exchanged with the keto group on the other. Pyridoxal phosphate is an important cofactor in transamination reactions, which play an essential role in providing amino acids as substrates for gluconeogenesis.

Decarboxylation reactions refer to reactions in which a carbon is removed from a carbon chain, typically released as carbon dioxide. Vitamin B6 is an important cofactor in decarboxylation reactions.

Vitamin B6 is a required coenzyme for glycogen phosphorylase, which catalyzes the rate limiting step in glycogenolysis. This reaction releases glucose-1-phosphate molecules from glycogen, mobilizing the body’s glucose stores.

This enzyme catalyzes the conversion of homocysteine to cystathionine, and requires pyridoxal phosphate as a cofactor. Deficiency of vitamin B6 can lead to accumulation of homocysteine and cause homocystinuria.

Pyridoxal phosphate is a cofactor for the enzyme ALA synthase in the heme synthesis pathway. In this way vitamin B6 is crucial for the formation of heme which is incorporated into hemoglobin. Vitamin B6 deficiency can therefore lead to an anemia called sideroblastic anemia.

Vitamin B6 is required for the metabolic conversion of tryptophan to niacin. A vitamin B6 deficiency can impair this conversion and lead to niacin deficiency in the body.

Vitamin B6 plays an important role in several neurochemical pathways. These include the synthesis of neurotransmitters such as serotonin, dopamine, epinephrine, norepinephrine, and GABA. Histamine synthesis also depends on vitamin B6.