Water-Soluble Vitamins (Kaplan) Flashcards
What 3 enzymes require biotin? Pathways?
Pyruvate carboxylase - gluconeogenesis
Acetyl-CoA carboxylase - FA synth
Propionyl-CoA carboxylase - VOMIT
What are the substances metabolized by propionyl-CoA?
VOMIT
Val, Odd-chain FAs, Met, Ile, Thr
What is the most common cause of biotin deficiency?
daily consumption of raw eggs
What 2 enzymes of glucose metabolism require thiamine?
pyruvate d.h. and α-ketoglutarate d.h.
What is the cardiac pathology in wet beriberi?
dilated cardiomyopathy –> decreased EF
What enzyme’s function is tested to Dx thiamine deficiency? Why?
transketolase - Thiamine is the only cofactor it requires.
What dehydrogenase (not directly involved in the metabolism of glucose) requires thiamine?
branched-chain amino acid d.h.
What 5 cofactors are required by all α-keto acid dehydrogenases?
LIly is so PO' she ATE Fried Chicken Nuggets with Thugs. Lipoate FAD CoA NAD+ TPP
What are the main Sx of pellagra?
3 D’s
Diarrhea, Dementia, Dermatitis
Progressive peripheral neuropathy caused by thiamine deficiency is due to damage in what part of the CNS?
posterior and lateral columns of spinal cord
What vitamin must be taken w/ isoniazid therapy?
B6
What is the most common cause of B6 deficiency?
alcoholism
How does alcoholism cause B6 deficiency?
Hepatitis -> increased transaminase activity; transaminases require B6.
How does B6 deficiency cause a microcytic sideroblastic anemia?
B6 is required by δ-ALA synthase for hemesynthesis. No B6, no heme, iron builds up, sideroblastic anemia.
You can see B6 deficiency right on someone’s face. How?
Stomatitis, cheilosis
What are the neurological complications of B6 deficiency?
peripheral neuropathy, convulsions, hyperirritability
Pt on parenteral nutrition develops corneal neovascularization, cheilosis, and a magenta-colored tongue. ¿Qué pasó?
Riboflavin deficiency
What does Vit C have to do w/ iron absorption?
Along w/ H+, converts Fe3+ to Fe2+ in the stomach.
What neurotransmitters rely on vitamin C for their production? Enzyme?
catecholamines - dopamine hydroxylase
Pantothenic acid is required for the production of ______.
CoA
