T4 biochem Flashcards
what are 3 forms of vitamin B6?
-pyridoxine (alcohol form)
-pyridoxal (aldehyde form)
-pyridoxamine (amine form)
what is active form of vitamin B6
pyridoxal phosphate (PLP)
what are the physiological importance of pyridoxine?
-synthesis of neurotransmitter such as serotonin, dopamine epi, nore
-amino acid metabolism (transamination, deamination)
-carbohydrates metabolism
-synthesis of heme
-lipid metabolism
what are the causes of vitamin B6 deficiency
-under isoniazid treatment (pts with TB)
-women taking oral contraceptive
-alcoholic
-infant fed formulas low in B6
complication of vitamin B6 deficiency
-neuropathy
-pellagra
-irritability, convulsion and peripheral neuritis
-epileptiform convulsion in infant
-hypochromic microcytic anemia
-impaired growth in children
recommended daily allowance of vitamin B6
1.4-2.0 mg/day
what are the component of vitamin B5
panthoic acid
beta alanine
what are the function of vitamin B5
-it is component of coenzyme A (important in transfer of acyl group)
-it is component of the acyl carrier protein ACP
which vitamin containing heterocyclic sulfur
vitamin H (Biotin)
mention 2 rings that formed in the biotin structure
-imidazole ring
-thiophene ring + valeric acid side chain
mention 2 vitamins that can be synthesized by intestinal bacteria?
vitamin H and vitamin K
what are the causes of biotin deficiency / vitamin H deficiency?
-long term antibiotic therapy which deplete intestinal bacteria
-consumption of excessive raw eggs (20 eggs/day to develop the deficiency syndrome) in athlete avidin high affinity to biotin prevent absorption
manifestation of vitamin H deficiency
dermatitis of the extremities
thinning or loss of hair
muscle pain and depression
what are the functions of biotin ?
carboxylation of pyruvate to oxaloacetate
carboxylation of acetyl CoA to malonyl CoA
