Exam - Biotin Flashcards
1
Q
supplement label
A
converts carbs, protein, fats to energy
2
Q
2 sources of biotin
A
- biotin made by intestinal bacteria
- biotin found in foods bound to proteins
3
Q
what must occur before absorption
A
must be removed from proteins - proteolysis by pepsin in stomach
4
Q
how is free biotin absorbed
A
to near completion - alcohol inhibits biotin absorption
5
Q
what percentage of biotin circulates in blood free form
A
80%
6
Q
how is a little bit of biotin circulating in blood
A
bound to albumin
7
Q
what are the 3 key reactions involving biotin
A
- pyruvate carboxylation
- malonyl CoA formation
- conversion of propionate into glucose (ruminants)
8
Q
2 steps of biotin-mediated carboxylation reaction
A
- carboxylate the N in the biotin ring structure
- transfer the carboxyl group to another molecule
9
Q
what does the carboxyl group of biotin interact with in carboxylation
A
the NH2 group of a lysine side chain
10
Q
what are B-vitamins important for
A
energy metabolism
11
Q
what B vitamin is biotin
A
B7
12
Q
what B vitamin is thiamine
A
B1
