Class Notes (835,308)
Canada (509,087)
Nutrition (899)
NUTR 3330 (14)
Lecture

VITAMIN B6.docx

4 Pages
132 Views
Unlock Document

Department
Nutrition
Course
NUTR 3330
Professor
Alison Duncan
Semester
Fall

Description
VITAMIN B6 PYRIDOXINE - 6 related compounds: pyridoxal, pyridoxine, pyridoxamine and their phosphates - phosphorylated in foods: phosphate removed by intestinal enzymes - well absorbed passively - taken up by tissues and re-phosphorylated - major metabolite, 4-pyridoxic acid, excreted in urine CO-ENZYME FORM - pyridoxal phosphate (PLP) - riboflavin needed to convert pyridoxine → PLP - heavily involved in amino acid metabolism METABOLIC ROLE Amino Acid Metabolism - primary role o transamination, R-group conversion (serine/glycine), decarboxylations - many aspects of intermediary metabolism; particularly GNG (gluconeogenesis) - kyurenine pathway = tryptophan metabolism = synthesis of niacin (B ) 3 Schiff Base - vitamin B 6alling card - allows PLP to effectively facilitate amino acid metabolism - PLP binds to enzyme between PLP aldehyde group and enzyme amino group o forms imine group H R-C=N-R Nervous System - synthesis of neurotransmitters (requires PLP dependent enzymes) - examples: serotonin, dopamine, GABA - tryptophan → serotonin - vitamin B 6eficiency = neurological problems – infant formula did not have enough B which6 caused seizures in infants Hormone function - PLP binds to steroid hormone receptors (on plasma membrane in cytosol and on nucleus) o inhibits binding of hormones, decreases effects o steroid responsiveness lower in B s6fficient versus deficient animals o can modulate steroid hormone Glycogen Breakdown - PLP involved in glycogenolysis (glycogen → glucose) o coenzyme for glycogen phosphorylase VITAMIN B6 PYRIDOXINE Red Blood Cell Formation and Function - PLP acts as coenzyme involved in synthesis of heme - Pyridoxal (PL) and PLP able to bind to Hb o affects ability to pick up and release O 2 o impact on normal oxygen delivery to tissues is not known Immune function - not clear - likely related to PLP role as coenzyme for enzymes involved in mobilization of single-carbon functional groups o one-carbon metabolism/transfer of one carbon unit o serine/glycine interconversion – serine OH-methyltransferase - synthesis of nucleic acids - B 6eficiency = IL-2 = decreased lymphocyte proliferation ASSESSING VITAMIN B STAT6S Load Tests (want to max out
More Less

Related notes for NUTR 3330

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit