Chapter 9: Vitamin B9 (Folate) Flashcards
other names:
folate
folacin
citrovorum factor
pteroylglutamic acid
lactobacillus casei factor
vitamin m
vitamin bc
factor u
folate (b9)
folate (b9) - chemistry
bring _____ crystalline compound
yellow
folate (b9) - chemistry
slightly soluble in _____
water
folate (b9) - chemistry
easily oxidized by _____
acids
folate (b9) - chemistry
sensitive to _____
light
folate (b9) - chemistry
made up of 3 distinct parts
pteridine, para-amino benzoic acid, glutamic acid
folate (b9) - chemistry
simplest form is _____ (PGA)
pteroylmonoglutamic acid (PGA)
folate (b9) - chemistry
folic acid usually occurs as _____, having 2-7 glutamic acid residues
polyglutamate derivatives
folate (b9) - chemistry
in the presence of ascorbic acid and niacin, PGA becomes (THF)
tetrahydrofolate
folate (b9) - chemistry
amethopterin, aminopterin, tetrahydrominophen, pytroylaspartic acid
antagonist of folate b9
folate (b9) - absorption, transport, and utilization
- _____ residues must first be removed to absorb the polyglutamate form of folate in foods
glutamic acid
folate (b9) - absorption, transport, and utilization
- hydrolysis of glutamic acid residues in the interstitial mucosal cells by _____ (or folate hydrogenase - a lysosomal enzyme)
conjugase
folate (b9) - absorption, transport, and utilization
- reduction of the free folic acid to THF by the enzyme _____ and transported in the blood mainly as N-methyl THF for distribution to the different body cells
dihydrofolate reductase
folate (b9) - absorption, transport, and utilization
- reduction of the free folic acid to THF by the enzyme dihydrofolate reductase and transported in the blood mainly as _____ for distribution to the different body cells
N-methyl THF
folate (b9) - absorption, transport, and utilization
- stored as THFs are mainly in the polyglutamate form in the _____
liver
folate (b9) - absorption, transport, and utilization
- stored as THFs are mainly in the _____ in the liver
polyglutamate form
folate (b9) - absorption, transport, and utilization
- _____ are more active than the monoglutamtes as coenzymes due to their greater binding ability with the enzyme
polyglutamates
folate (b9) - absorption, transport, and utilization
- for the folate coenzyme to function, the methyl group must be released from methyl-THF by an enzyme methionine synthetase that needs _____ for its activity
vitamin b12
folate (b9) - absorption, transport, and utilization
folate is excreted in the _____ (2)
urine and bile
folate (b9) - functions
folate functions as a coenzyme in the THF form in reactions, which transfer _____ (such as the methyl group CH3) from one compound to another
THF derivatives serves as donors of one-C units in the following biologic reactions
one-carbon units
folate (b9) - functions
synthesis of amino acid (3)
methionine, histidine, and serine
folate (b9) - functions
conversion of phenylalanine to tyrosine
folate b9
folate (b9) - functions
formation of the heme group of hemoglobin
folate b9
folate (b9) - functions
synthesis of the purine and pyrimidine bases needed for the formation of _____ and _____
DNA and RNA
folate (b9) - functions
formation of the vitamin-like compound choline from _____
ethanolamine
folate (b9) - functions
conversion of niacin to _____, in the form in which it is excreted
n-methyl nicotinamide
folate (b9) - functions
folate may play a role against these type of cancers
breast and pancreas
folate (b9) - functions
folate may protect the _____ from the damage of homocyteine, which promotes blood clot
heart
folate (b9) - interactions with other nutrients
_____ protects the folate coenzyme from oxidative destruction
there must be sufficient vitamin b12 for the activity of the methionine synthetase, the enzyme that reduces the methyl group from n-5-methyl-thf to form methionine from homocysteine
vitamin c
folate (b9) - interactions with other nutrients
supplement of folate decreases _____ absorption
zinc
folate (b9) - deficiency
diets that lack quantity and quality of _____ and _____ are at risk for inadequate folate intake
green leafy vegetables and legumes
folate (b9) - deficiency
folate requirements are increased/decreased during pregnancy esp. in the first couple of weeks of gestation
increased
folate (b9) - deficiency
folate deficiency is highly associated with the risk of _____ (malformation of the brain and spinal cord that result in disability or death ex. spina bifida or anencephaly)
neural tube defects in growing fetus
a condition that affects the spine and is usually apparent at birth
spina bifida
a fatal condition where a baby is born without parts of the brain and skull
anencephaly
folate (b9) - deficiency
a _____ will provoke folate deficiency because it means vitamin b12 is not available to donate its methyl group to convert folate into its active form
vitamin b12
folate (b9) - deficiency
other deficiencies:
-megaloblastic anemia or macrocytic anemia
-glossitis
-gastrointestinal upsets
-impairment of histidine metabolism
folate deficiency
megaloblastic anemia is also known as
macrocytic anemia
folate (b9) - toxicity
high doses of folate has adverse effects
greatest risk of overdosing with folate arises from its close relationship with _____
vitamin b12
folate (b9) - recommended intake
for children (6-12 y/o) males and females
300 ugDFE
folate (b9) - recommended intake
for 13 - >70 y/o males and females
400 ugDFE
dfe meaning
dietary folate equivalent
folate (b9) - recommended intake
for pregnancy
400 ugDFE +200
folate (b9) - recommended intake
for lactating
400 ugDFE +150
folate (b9) - food sources
dark green leafy vegetables (alugbati, gabi malunggay, saluyot, sitao, talinum), wheat germ, legumes, seeds, oranges, strawberries, and organ meats (liver)
b9 sources
