Thiamin Flashcards
What 3 important reactions use thiamin as a cofactor
Pyruvate dehydrogenase complex
Alpha ketoglutarate dehydrogenase complex
Branched chain alpha keto acid dehydrogenase complex (BCKAD)
What is thiamins role in those 3 important pathways?
Oxidative decarboxylation
Pyruvate dehydrogenase complex function
Converts pyruvate to Acetyl CoA
Alpha ketoglutarate dehydrogenase complex function
Converts alpha ketoglutarate to succinyl CoA within the tca cycle
Branched chain alpha keto acid dehydrogenase complex (BCKAD) function
Complex is a combination of enzymes responsible for the degradation of the BCAAs
What is the mechanism of action at which thiamin reacts with pyruvate, alpha ketoglutarate and other alpha keto acids
Forms a carbanion, which attacks the carbonyl group
Then thiamin attaches to the compound
2 characteristics of dry beri beri
Low intake of thiamin
Coupled with
High carb intake
Why would an individual experience wasting with a high carbohydrate diet and low chronic thiamin intake?
Pyruvate from carbs cannot be converted to acetyl CoA with thiamin deficiency
Does wet beriberi involve a high carb diet?
No
2 characteristics of wet beriberi
Pitting edema
Heart problems
Characteristic of acute berberi
Primarily seen in infants from a mother suffering from beriberi
Wernicke-korsakoff syndrome is prevalent in?
Alcoholics
Thiamin deficiency is often associated with alcoholics for what 3 reasons
Decreased food intake
Liver damage where thiamin is converted to cofactor form
Inhibit intestinal transporters for thiamin (absorption)
What are 3 symptoms of wernicke-korsakoff syndrome
Optalmoplegia- paralysis of ocular muscles
Nystagmus- constant, involuntary eye movement
Ataxia- impaired muscle coordination
What is thiamins co enzyme role
Energy transformation
