Vitamin B2 - Riboflavin

Question 1

origin of riboflavin

Answer 1

1. plant: grain, green vegetable -> riboflavin
2. animal: meat, egg, milk -> FAD, FMN
3. microbial synthesis

Question 2

excretion

Answer 2

in form of riboflavin in urine

Question 3

transport

Answer 3

bound to albumin

Question 4

activation of riboflavin

Answer 4

• -> FAD, FMN

- prosthetic gr. of dehydrogenases

Question 5

found

Answer 5

in any cell

Question 6

biochemical role

Answer 6

1. FAD⁺FADH2
2. Anarerobe dehydrogenases: oxidases!
3. Aerobe dehydrogenases: dehydrogenases!

Question 7

Anarerobe dehydrogenases

Answer 7

oxidases: uses reduction oxidation of FADH2 to reduce O2 to H2O2
- xanthine oxidase
- D-aa oxidase
- mono-aa oxidase

Question 8

Aerobe dehydrogenases:

Answer 8

dehydrogenases: incdirect oxygen is made by making water and (2)ATP
- NADPH dehydrogenase (1st complex in resp chain, FMN is made)
- succinate dehydrogenase (2nd complex in resp chain, FADH2 is made)
- Fatty acyl CoA dehydrogenase (B-ox, FADH2 is made)

Question 9

deficiancy

Answer 9

1. disrupts the steps of intermed metabolism (less energy gain)
2. dermatitis, hair/feather loss, poor growth

Question 10

animals escp. affected

Answer 10

mammals: fatty liver, hair loss
poultry: “curled toe disease”: leg paralysis, hair/feather loss

Question 11

which feed has less riboflavin

Answer 11

grains