Exam - Riboflavin

Question 1

supplement label (B3)

Answer 1

converts carbs, proteins, fats to energy

Question 2

sources of riboflavin

Answer 2

rich in foods of animal origin

Question 3

what is riboflavin degraded with

Answer 3

sunlight

Question 4

examples of bound riboflavin

Answer 4

flavin mononucleotide (FMN)
flavin adenin dinucleotide (FAD)

Question 5

what must occur to riboflavin that is bound to proteins before absorption

Answer 5

it must be released - done by HCl

Question 6

where is free riboflavin absorbed

Answer 6

from gut lumen by an active transport mechanism: riboflavin transporter 2 (RFT2)

Question 7

how does riboflavin, FMN and FAD get transported in body

Answer 7

bound to proteins - particularly albumin

Question 8

does riboflavin get stored in the body

Answer 8

a little bit in liver, kidney and heart

Question 9

where does extra riboflavin generally go

Answer 9

generally it gets excreted in urine

Question 10

how long do sufficient amounts of riboflavin last in body

Answer 10

2-6 weeks

Question 11

where are FMN and FAD made

Answer 11

in cells

Question 12

what is the primary form of riboflavin in the body

Answer 12

FAD (60-95%)

Question 13

what are FMN and FAD involved in

Answer 13

redox reactions

Question 14

what is FMN and FAD production positively regulated by

Answer 14

T3 hormone - increases activity of the flavokinase enzyme

Question 15

what element is a part of the enzymes for riboflavin metabolism

Answer 15

Mn or Mg

Question 16

what is FMN considered

Answer 16

nucleotide

Question 17

what is FAD considered

Answer 17

a dinucleotide

Question 18

where does riboflavin function

Answer 18

many biochemical pathways

Question 19

what is the primary difference between FMN/FAD and NAD(P) in electron transfer

Answer 19

FMN?FAD are bound to the active site of an enzyme

Question 20

what does FAD do to regenerate glutathione

Answer 20

accepts 2 electrons from NADPH and temporarily becomes FADH2

Question 21

what does reforming glutathione require

Answer 21

both niacin and riboflavin

Question 22

when does the signs of riboflavin deficiency appear

Answer 22

after 3-4 months

Question 23

term for riboflavin deficiency

Answer 23

ariboflavinosis

Question 24

why is deficiency relatively common when dietary intake is insufficient

Answer 24

because riboflavin is continuously excreted in urine

Question 25

symptoms of riboflavin deficiency

Answer 25

cracked/red lips
inflammation of mouth lining and tongue
mouth ulcers
cracks at the corners of mouths

Question 26

populations at risk for deficiency

Answer 26

people with hypothyroidism/thyroid disease
chronic alcoholism
lactose intolerant

Question 27

is there an upper limit for riboflavin

Answer 27

no