B Vitamins Flashcards
Thiamin Major Functions
part of a coenzyme
- aids in the breakdown to provide energy
- needed to convert pyruvate into acetyl-CoA
thiamin is a coenzyme is especially important for nerve function
thiamin occupies a special site on nerve cell membranes; hence it is available to breakdown any needed glucose
thiamin is needed for the synthesis of …
neurotransmitters
thiamin is needed for the metabolism of
other sugars and amino acids
thiamin is required for the synthesis of
ribose and deoxyribose
Beriberi
deficiency disease of thiamin
- inflammatory or degenerative changes of the nerves, digestive system and the heart
- without thiamin, glucose can’t be used normally
- nerve impulses can’t be transmitted
symptoms of beriberi
loss of sensation in the hands and feet, edema, muscle weakness & poor coordination, changes to the heart, poor short-term memory and confusion
alcoholics at risk for beriberi
ethanol intereferes with the absorption of thiamin and hastens is excretion in the urine
Riboflavin
is a part of two coenzymes
- that act as electron carriers
- they function in reactions needed to produce ATP from CHO, fat and protein
Riboflavin is involved n converting some vitamins into their active form
such as folate, niacin, vitamin B6, and vitamin K
Riboflavin supports
skin health and vision
symptoms of riboflavin deficiencies
cheilosis - cracking & redness of the lips or around the corners of the mouth
- flaking skin around the nose, eyebrows & earlobes
- glossitis - inflammation of the tongue (red & swollen)
- eyes - increased sensitivity to light; burning, tearing, and itching of the eyes
Niacin
is part of two coenzymes
- especially in the metabolism of CHO, fat, and alcohol
- coenzymes needed for the synthesis of fatty acids and cholesterol
body can make niacin from
tryptophan
-reason why recommendation are expressed as “niacin equivalent”
Niacin Equivalent
the measure that takes into account the available tryptophan
Pellagra
niacin deficiency diseases
-fatigue, decreased appetite, and indigestion
Symptoms of Pellagra (the four D’s)
Diarrhea, Dermatitis, Dementia and it left untreated Death
those at risk for Pellagra
poorly nourished, those with alcohol addiction
Niacin is sometimes prescribed in larger doses as a treatment for
lower blood lipid levels
Biotin
plays an important role in energy metabolism
-as a coenzyme, it carries activated CO2 that is critical in keeping Citric Acid Cycle running.
Biotin is needed in the synthesis of glucose
from non-carbohydrate sources such as amino-acids and glycerole
biotin is needed in the synthesis of _________ and the breakdown of certain fatty acids and amino acids
fatty acids
it can be made in the body by ________ in the GI tract
bacteria
deficiency in Biotin is…
rare
symptoms of biotin deficienceis
nausea, thinning hair, loss of hair color, tingling in hands or feet, red skin rash, depression, lethargy, hallucinations
Pantothenic Acid
a component of a coenzyme
pantothenic acid assists with the making of _________ which is needed in the TCA cycle and ultimately ATP formation
Acetyl Co-A
pantothenic Acid is needed in the synthesis of
making lips, neurotransmitters, steroid hormones and hemoglobin
deficiency in Pantothenic Acid is….
rare
Vitamin B6
role in amino acid & protein metabolism
Vitamin B6 is a
coenzyme
Vitamin B6 is needed for
deamination reactions
-removal of NH2; reamining carbon comound used for energy
Vitamin B6 is involved in the synthesis of
neurotransmitters
-
Vitamin B6 is needed for the synthesis of lipids that are part of the
lipids in the myelin sheath
Along with folate and B12, B6 is needed for
senythesis of hemoglobin and white blood cells
B6, B12, and folate conversion of _________ to cysteine
homocysteine
Vitamin B6 is needed to convert tryptophan into
niacin
Vitamin B6 is needed for breaking down glycogen to release ______ into the blood
glucose
Vitamin B6 deficiency
poor growth, skin lesions, decreased immunity, anemia, neurologcial symptoms
Folate (and B12) is needed for the making of
new cells
- synthesis of DNA and RNA
Folate (and B12) are needed for the replication of
DNA
Folate (and B12) are required for the formation and maturation of _________ and ____________ and for the formation of hemoglobin
red blood cells and white blood cells
Folate is needed for the reduced risk of
neural tube defects
what is folic acid and is it readily absorbed?
- synthesis form of folate
- readily absorbed
- bioavailability is almost twice that of folate
Neural Tube Defects
malformation of the brain, spinal cord or both during embryonic development
Spina Bifida is not a Common NTD
three membranes that surround the spinal cord often protrude form the spin as a sac
-portion of the spinal cord is sometimes in the sac
mild cases are not noticeable
deficiency in folate can result in an anemia called
megalobastic or macrocytic anemia
- lack of folate
- red blood cells become larger
- fewer matrue red blood cells
those at risk for folate deficeicency
alcoholics, pregnant females, elderly, and smokers
Vitamin B12 is required for
making new cells (DNA and RNA synthesis)
Vitamin B12 is needed for the maintenance of
myelin sheath
Vitamin B12 are also needed to convert _______ to an active coenzyme
- Folate
- conversion of homocysteine
Vitamin B12 in food is bound to
protein
two people at risk for B12 deficiency
Vega and older adults
