Biotin

Question 1

Wilder

Answer 1

observes that yeast
require a special substance to grow;
names it “bios”.

Question 2

Boas-Fixen

Answer 2

raw egg
whites to rats= dermatitis and loss of
hair, cured by a protective liver
factor.

Question 3

Gyorgy

Answer 3

discovers the liver

factor and calls it Vitamin H.

Question 4

Kogl and

Tonnis

Answer 4

extracts a crystalline growth
factor from dried egg yolk and names
it biotin.

Question 5

Uptake:

Answer 5

By liver and other tissues VI
SMVT. Leukocytes via
monocarboxylate transport 1 (MCT1)
and solute carrier family 19 member
3 (SLC19A3).

Question 6

Coenzyme

Answer 6

caboxylases, transferring

single-carbon units as CO2.

Question 7

Noncoenzyme

Answer 7

roles in cell

cycle and gene expression.

Question 8

Propionyl Co-A carboxylase-

Answer 8

catabolism of the amino

acids isoleucine, threonine, and methionine.

Question 9

Acetyl Co-A Carboxylase I and II

Answer 9

Involved in first
committed step of fatty acid synthesis. Acetyl 
Malonyl

Question 10

Β-Methylcrotonyl-CoA carboxylase

Answer 10

leucine catabolism.

Question 11

Non-coenzyme functions-

Answer 11

Cell cycle. Covalently
attaches to histones (biotinylation). Associated with
cell proliferation. Gene Silencing. Cellular response to
DNA damage.

Question 12

Clinical symptoms

Answer 12

thinning of hair, loss of hair color,
skin rash-scaly and red (eyes, nose, and mouth),
depression, lethargy, hallucinations. Infants:
hypotonia, developmental delay, mental retardation.

Question 13

Status

Answer 13

Urinary biotin and biotin metabolites.

Question 14

Transport:

Answer 14

80% as free biotin. Remained

bound to albumin, α & β- globuin

Question 15

Excretion:

Answer 15

as biotin and metabolites in

urine

Question 16

RDA

Answer 16

30μg

Question 17

Toxicity

Answer 17

none

Question 18

Food

Answer 18

well distributed