Vitamin B6 and B12 Flashcards

4305233609	B6 absorption	-Requires dephosphorylation -Primarily in the jejunum	0
4305234487	Passive diffusion of free forms	Physiological conditions	1
4305235160	Phoshorylated forms are in excess	Absorbed without dephosphorylation	2
4305238242	Muscle stores	75-80%	3
4305241284	Liver stores	5-10%	4
4305242271	Phosphorylation	Prevents the diffusion of the vitamin out of cells	5
4305243107	Transamination	-Is the transfer of an amino group (-NH2) from one amino acid to an alpha-ketoacid -Important for the synthesis of non-essential amino acids	6
4305244967	Binding to proteins	Prevent the dephosphorylation	7
4305246222	Deamination	Is the removal of an amino group (-NH2) for example an amino acid and release as ammonia	8
4305246794	Decarboxylation	-Is the removal of carboxy group (-COO-) from an amino acid or other molecule -For example synthesis of gamma-aminobutyric acid (GABA) from glutamate	9
4305247932	Meat products	Adenosylcobalamin	10
4305247933	Milk products	Methylcobalamin	11
4305248668	Stomach	Pepsin and HCL release cobalamins from polypeptides	12
4305249605	R proteins	-Found in saliva and gastric juices -Binds to vitamin and protects it from bacterial use	13
4305250149	Intrinsic factor	Made and released in stomach but functions in intestine	14
4307560347	B6 deficiency stages	1. serum 2. cell concentrations diminish 3. biochemical deficiency occurs 4. Megaloblasic macrocytic anemia	15
4307560348	Serum	Low levels of holotranscobalamin II	16
4307562551	Biochemical deficiency	1. decreased dna synthesis 2. elevated homocysteine in serum 3. elevated methylmalonic acid in serum	17
4307567053	Megaloblasic macrocytic anemia	May be caused by pernicious anemia 1) autoimmune condition 2) antibodies attack parietal cells 3) decreased IF production	18
4307568877	Severe B12 deficiency	a. Neurological symptoms b. Degeneration of spinal cord c. Presentation: absent reflexes, ataxia, no sense of touch d. results in: severe irreversible brain and nervous system damage, death	19