Exam -Thiamine

Question 1

supplement label for thiamine

Answer 1

converts carbs, proteins, fats to energy

Question 2

where is thiamine found

Answer 2

many foods including meats, whole fortified or enriched grain products

Question 3

what destroys thiamine

Answer 3

heat
alkaline environment

Question 4

how does thiamine exist in plants

Answer 4

free form

Question 5

how does thiamine exist in animals

Answer 5

phosphorylated form - active form (TPP)

Question 6

what must occur to TPP to be absorbed

Answer 6

phosphate group must be removed

Question 7

where does absorption occur

Answer 7

small intestine

Question 8

what is absorption controlled by

Answer 8

thiamine transporters

Question 9

how is TPP found in plasma

Answer 9

free form or bound to albumin

Question 10

what is TPP

Answer 10

thiamine pyrophosphate

Question 11

TPP production

Answer 11

thiamine undegoes enzyme reaction catalyzed by thiamine diphosphokinase to become TPP

Question 12

what is thiamine an important cofactor for

Answer 12

many enzymes:
pyruvate dehydrogenase
alpha-ketoglutarate dehydrogenase

Question 13

what are the 2 key oxidative decarboxylation steps that TPP is important in

Answer 13

1. pyruvate dehydrogenase complex
2. alpha-ketoglutarate dehydrogenase complex

Question 14

what do pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase require as cofactors

Answer 14

TPP
FAD
NAD
CoA

Question 15

what phase of the hexose monophosphate shunt is thiamine required for

Answer 15

the non-oxidative phase

Question 16

what do thiamine deficiencies interfere with

Answer 16

critical energy metabolism pathways - ultimately prevents ATP production and acetyl-CoA synthesis
accumulation of pyruvate, lactate and alpha-ketoglutarate in the blood

Question 17

dry beriberi

Answer 17

in adults due to chronic low thiamine intake - muscle weakness and affects nervous system

Question 18

wet beriberi

Answer 18

in children and young adults - more serious than dry and affects cardiovascular system

Question 19

acute beriberi

Answer 19

in infants
anorexia, vomiting, lactic acidosis, death

Question 20

who is susceptible to thiamine deficiency

Answer 20

chronic alcoholism
people who depend on polished white rice as major food source

Question 21

does thiamine have an upper limit

Answer 21

no