Biotin &

folacinPreapared by:

NasraEbtissam

Sukina

Vitamins are essential organic compounds

that the animal organism is not capable of forming itself, although it requires them in small amounts for metabolism.

Most vitamins are precursors of coenzymesprecursors of hormones

or act a antioxidants

Color atlas of biochemistry

Vitamin requirements

vary from species to species and are influenced by age, sex, and physiological conditions such as pregnancy, breast-feeding, physical exercise, and nutrition.

:Vitamins are classified as

The lipid-soluble vitamins include vitamins A, D, E, and K

the water-soluble vitamin include vitamins B1(thiamin) ,B2 (riboflavin),folic acid (folcine),

H(biotin) .

Color atlas of biochemistry

Biotin Vitamin

H

Vitamin H (biotin)

present in liver, egg yolk, and other foods. synthesized by the intestinal flora.

Harper’s Illustrated Biochemistry

Biochemical role of biotin:

In the body, biotin is covalently attached via a lysine side chain to enzymethat catalyze carboxylation reactions.

Biotin-dependent carboxylases include pyruvate carboxylase and acetyl-CoA carboxylase.

CO2 binds, using up ATP, to one of the two N atoms of biotin.

Play an important role in fat, amino acid,and carbohydrate metabolism.

Color atlas of biochemistry

Biotin deficiency

• Biotin deficiency is extremely rare.• Some potential causes of biotin deficiency are:

intravenous feeding .eating raw egg whites on a regular basis.carboxylase deficiency.Supplementing with biotin appears

• helpful for the treatment of this deficiency.

http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-biotin.html

Deficiency disease

Impaired fat and carbohydrate metabolism

alopecia and a characteristic scaly, erythematous dermatitis

Harper’s Illustrated Biochemistry, www.pubmed.com

Folacin

Folacin

*Folic acid, folate,vit.B9

*water-soluble vitamin

Source

Biochemical role -Essential role in

Metabolism

-Red blood cells, white blood cells, or cells of the intestinal mucous membrane

•pharmacotherapy

Biochemical role

monoglutamate

Small intestine

tetrahydrofolate

cobalamin-dependent reaction

Folacin (polyglutamate form )

pharmacotherapy

tetrahydrofolate

Biochemical role

choline

methionine

pyrimidine

carrier

purine

Biochemical role

-decrease the incidence of neural tube defects without masking occult vitaminB12 deficiency.

Deficiency of folacin

Causes:

Inadequate dietary intake

malnutrition

malabsorptionincreased utilization

Martindale

Risk factors:

*Pregnancy or lactation*malignancy

*liver disease*alcoholism

*chronic hemolytic anemia

*Elevated homocysteine level in the blood

http:/www.springboard4health.com

Symptoms:

*Sore mouth*Diarrhea

*Irritability and forgetfulness

Handbook of nonprescription drugs

Diseases

*Megaloblastic Anemia-

-Affects cells that are dividing rapidly -they have a large requirement for

thymidine for DNA synthesis.

-affects the bone marrow

http:/www.springboard4health.com

Diseases

*environmental carcinogens.

*promotes the breakage of chromosomes at fragile sties.

*prohibit normal differentiation and replication