Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Upcoming SlideShare
BIOTIN (B7)
Next

23

Share

Biotin ( vitamin B7) Egg white injury, Leiner's disease

Related Books

Free with a 30 day trial from Scribd

See all

Related Audiobooks

Free with a 30 day trial from Scribd

See all

Biotin ( vitamin B7) Egg white injury, Leiner's disease

  1. 1. BIOTIN (B7)CHEMISTRY FUNCTIONS AND DEFICIENCYPRESENTED BY Irma SuntooROLL NUMBER : 102DATE : 04/09/12
  2. 2. Table of Content Chemistry of Biotin Biosynthesis & Metabolism Storage, Excretion & Sources Metabolic Role of Biotin Deficiency Manifestations Deficiency Diseases References
  3. 3. Biotin ( vitamin B7)SYNONYMS : bios, vitamin H, co-enzyme R, Anti-egg white injury factor.CHEMISTRY• Heterocyclic monocarboxylic acid• Sulphur containing water soluble B-vitamin
  4. 4. • 2 rings : Imidazole ring & thiophenederivative.• Occurs in free form & bound form in tissuesand food.• Exists as biocytin, oxybiotin and desthiobiotinin bound form.
  5. 5. • Depending on the side chain :1. Alpha-biotin2. Beta biotino Covalently attached to epsilon amino groupof lysine to form biocytin (ε-N-Biotinyl lysine)• Biocytin is present in tissues.• Desthiobiotin and oxybiotin: These arebiologically active in certain strains of yeastand bacteria.
  6. 6. Biosynthesis and Metabolism• Biotin is not synthesised in humans.• It has to be taken in the diet.• Synthesized by bacterial flora of intestine,fungus and yeast.• Formed in leaf and root in plants• Co-enzyme R is a growth essential for thenitrogen-fixing organisms.
  7. 7. STORAGE• Stored to a limited extent in Liver & kidneys.SOURCES• Widely distributed in plants & animals.Plants : leafy vegetables & cereals.Animals : liver, kidney, milk & egg yolk.
  8. 8. ExcretionIt is excreted in urine, faeces and in milksecretion.Metabolic role of biotin1. Biotin acts as coenzyme forcarboxylation reactions catalysed byCarboxylases.
  9. 9. • Biotin is first converted to carboxy-biotincomplex by reaction with bicarbonate & ATP.• CO2-biotin complex is the source of activeCO2 which is transferred to the substrate.
  10. 10. Examples of Carboxylation reactions :1) Conversion of pyruvate to OAA.Biological Significance• It is the first reaction of gluconeogenesis.• OAA can be used for glucose production or for thefunctioning of TCA cycle depending on need of cell.
  11. 11. 2) Carboxylation of propionyl coABiological significance• Succinyl CoA enters TCA cycle for complete oxidation toprovide energy.• Propionyl CoA is glucogenic in nature.
  12. 12. 3) Conversion of Acetyl CoA to Malonyl CoABiological Significance• First &rate limiting reaction of FA biosynthesis.• In absence of biotin, FA synthesis is enormously affected.
  13. 13. 4) Carboxylation of B-methyl crotonyl CoABiological Significance• Important reaction of Leucine Metabolism.• Biotin deficiency impairs leucine metabolism greatly.
  14. 14. Role of Biotin in cell division• Required for cell division & tissueproliferation.• Has an active role in maintaining texture ofskin, hair and nails. (Beauty vit)
  15. 15. Deficiency of BiotinVery rareOccurs except under 2 conditions:1. Congenital deficiency• It is due to deficiency of enzymeholocarboxylase synthetase.
  16. 16. Deficiency of the HCS enzyme makes thecarboxylases inefficient, precipitating all themanifestations of biotin deficiency.Also, CO2 transfer reactions are grosslyaffected.Clinical Manifestations• Growth retardation• Dermatitis• Loss of hair• Greying of hair• Abdominal discomfort and diarrhea
  17. 17. Loss of hair dermatitisGreying of hair
  18. 18. Treatment :No permanent cure.Only symptomatic cure is given.2) Acquired biotin deficiency• TWO TYPES :I. Leiner’s DiseaseII. Egg-white Injury
  19. 19. • Leiner’s Disease Seen in infants while being exclusively breast-fed and infants having chronic diarrheas. Due to chronic diarrhea, dietary biotin is notabsorbed. Breast milk has low content of biotin. Such infants present with manifestations ofbiotin def. in form of dermatitis and easilypeeling of skin.
  20. 20. • Treatment :Supplementation of biotin. However, primarilythe cause of the recurrent diarrhea has to betreated.Easy peeling of skin Leiner’s disease
  21. 21. Egg-white Injury• Due to excessive consumption of raw eggsmainly egg white.• Protein Avidin (anti-vitamin) binds with biotinand inactivates it.• Cooked egg-white is found not to be toxicsince Avidin is heat-liable and boiling of eggsinactivates Avidin.• 1 molecule of Avidin binds to 4 molecules ofbiotin.
  22. 22. References• Class Notes.• http://www.namrata.co/functions-of-biotin/• Wikipedia• Mn Rana Shinde
  • LuckyPanchal3

    Sep. 23, 2021
  • KaranArora259

    Jul. 3, 2021
  • AdarshNirnejak

    Mar. 17, 2021
  • ssuserb77b24

    Sep. 16, 2020
  • HarmanjeetSaini1

    May. 31, 2020
  • ShaiMaa17

    Apr. 6, 2020
  • Nupesh99

    Feb. 23, 2020
  • Harshit122103

    Mar. 15, 2019
  • RidanyaMadeswaran1

    Jun. 22, 2018
  • bobwalter16

    Apr. 1, 2018
  • RanavathReddy

    Mar. 26, 2018
  • YogitaBhansali

    Nov. 18, 2017
  • billalnovo

    Nov. 11, 2017
  • AdelElabedeen

    Jun. 9, 2017
  • PlatyPrizzy

    Apr. 20, 2017
  • snowjean

    Jan. 4, 2017
  • ethelmay

    Oct. 15, 2016
  • verawati13

    Apr. 11, 2016
  • sstare

    Nov. 11, 2015
  • vinoth97

    Oct. 7, 2015

Views

Total views

10,250

On Slideshare

0

From embeds

0

Number of embeds

5

Actions

Downloads

0

Shares

0

Comments

0

Likes

23

×