B vitamins Flashcards
T/F: does B1 work with B2, B3, and B5 in the pyruvate dehydrogenase reaction?
True
T/F: B-vitamins may use phosphatases to help facilitate absorption?
True
T/F: a thiamin deficiency can adversely affect nerve conduction through decreased production of acetylcholine?
True
What vitamin coenzymes forms are based on a nucleotide structure?
NADPH, FADH2, FMN
What vitamin coenzymes are needed in the Heme synthesis pathway?
B6, B7
if a tryptophan load test was done on a patient who was deficient in B6, what would happen to the production of NAD+ and excretion of xanthurenic acid?
decreased production on NAD+
Increased excretion of xanthurenic acid.
B6 is used to make all of the following NTs except:
a. GABA
b. Serotonin
c. Dopamine
D. acetylcholine
B6 does not make acetylcholine
IF (intrinsic factor) : what is the role of B12?
IF is bound to B12 and internalized via receptor-mediated endocytosis
All citric acid cycle dehydrogenases produce NADH except for?
succinate dehydrogenase which produces FADH2
what are the physiologival effects of nicotinic acid from B3?
causes vasodilatory prostaglandin release, responsible for the niacin flush
causes enhanced fibrinolysis to help prevent clot buildup and improve blood flow
improves lipid profile: decrease VLDL/ DL and increase HDL
increased histamine release
what enzyme blocks the production of vascodilatory prostaglandins in the niacin flush?
COX (cyclooxygenase).
so to prevent this use NSAIDs that inhibit COX for example aspirin.
how can nicotinic acid be applied to Raynaud’s phenomenon?
vasodilatory mechanism
why would nicotinic acid be harmful for someone with peptide ulcer disease?
NAC can cause increased histamine release, which mediates inflammation and vasodilations, increased histamine released makes symptoms worse because it stimulates gastric acid secretion irritating the ulcerated mucosa and increasing pain or bleeding
why would nicotinic acid potentially lead to hyperglycemia?
decreased phosphorylation of glucose by glucokinase which regulates blood glucose by phosphorylation in the liver. With decreased activity there is less glucose uptake and storage in liver, leaving more in bloodstream.
to avoid all of these side effects of nictonic acid, what is an alternative?
nicotinamide!