3. 3
Riboflavin (B2)
It is also called as beauty vitamin.
it is yellowish green fluorescent compound
soluble in water.
The word riboflavin is derived from 2 sources
ribose – means many ribose sugar found in
several vitamins
flavin – yellow.
It is widely involved in oxidation-reduction
reaction.
10. 10
Absorption & excretion
It is readily absorbed from intestinal tract
It is carried to tissue of the body &
incorporated into the cell enzymes.
It is stored in liver, kidney & heart.
Excretion – urine & sweat
12. BIOCHEMICAL FUNCTIONS OF
RIBOFLAVIN:
A- Biochemical role of FMN as a coenzyme
1. FMN as a part of redox potential
2. FMN is a coenzyme for L-amino acid
oxidases:
13. 3. FMN being a part of Cut. C reductase
4. FMN also accepts 2H+
from NADH+H+
5. FMN is a coenzyme for Warburg’s yellow
enzyme [a component of respiratory
chain]
14. B- FAD is a coenzyme for the following
enzyme:
Like FMN, FAD is also is a part of
mitochondrial respiratory chain
15. 1. D-aminoacid oxidases: The enzymes
catalyze reaction similar to L-aminoacid
oxidases but with FAD as coenzyme.
2. Aldehyde oxidase
3. Acyl-CoA dehydrogenase of the β
oxidation of fatty acids
16. 4. Succinate dehydrogenase, an enzyme of
citric acids cycle and converts succinate
to fumarate in mitochondria
5. Xanthine oxidase present in milk, small
intestine, kidney converts purine bases to
uric acid
17. 6. Glucose oxidase prepared from fungi
7. Glycine oxidase which oxidative
deaminates glycine to glyoxylic acid and
ammonia
18. Riboflavin-B2
Involved in energy metabolism; part of two
co- enzymes,FMN and FAD
Participate in citric acid cycle and beta
oxidation and electron transport
Remove ammonia during deamination of
some amino- acids
20. 20
Functions
It is essential for normal growth.
Metabolism – It is involved in the metabolism
of carbohydrates, fat & proteins.
Digestion – it helps in digestion
Nervous system – it helps in proper
functioning of Nervous system
22. 22
Deficiency
Ocular changes-
it consists of corneal vasodilatation,
superficial & interstitial keratitis.
Skin & nails –
it may also result in dull or oily hair. Oily
skin, premature wrinkle on face.
28. 28
SEBORRHEIC DERMATITIS
Red, scaly, itchy rashes
seen on
• scalp
• sides of nose
• eyebrows
• eyelids
• skin behind ears, middle of
chest
29. 29
Oral manifestation
Tongue:- in severe cases the tongue becomes
glazed & smooth due to complete atrophy of
the papillae.
Lips:- becomes red & shiny because of
desquamation of epithelium.
31. VITAMIN B2 (Riboflavin)
SOURCES:
Yeast
Whole grain
Dry beans and pea
Green vegetables
RDA: 1.5-1.8 mg/day in adults
FUNCTIONS:
In two active forms FMN and FAD serves as coenzyme in various reactions
DEFICIENCY
Cheilosis-fissuring at angle of the mouth
Glossitis-tongue smooth and purplish
Seborrhagic Dermatitis:scaly,greasy,desquamation
Eyes: corneal vascularization
Chronic alcoholics are susceptible to deficiencies.