Exam 3- Chapter 10 Flashcards
What are the fat soluble vitamins?
Vitamins ADEK
What are the water soluble vitamins?
All other vitamins that are not ADEK.
What factors affect bioavailability of nutrients?
Efficiency of digestion-declines w/ age Nutrition status of individual Method of food preparation Source of nutrient Other foods consumed at same time
What is the overall function of all B vitamins?
Provide energy for most functions of the body
What is the function of thiamin?
- ASSISTS ON ENERGY METABOLISM by converting pyruvate to AcetylCoA
- Part of coenzyme Thiamin Pyrophosphate
What foods are good sources of thiamin?
Enriched grains and pork
What groups of people are most affected by thiamin deficiency?
Malnourished individuals and alcoholics as well as bariatric patients
What is the disease Beriberi and what vitamin deficiency causes it?
- Lack of thiamin
- Dry beriberi affects nervous system
- Wet beriberi affects cardiovascular system
What are the functions of riboflavin?
- Aids in energy production by assisting in conversion of carbs to glucose.
- Serves as coenzymes FMN and FAD
What happens if you are deficient in Riboflavin?
-Inflammation of: Eyes, mouth, GI tract, and skin may occur.
What are great sources of riboflavin?
Liver, milk, broccoli, eggs.
What is the function of Niacin?
- Assists energy metabolism
- Serves as coenzyme in NAD and NADH form.
What molecule can be made out of excess niacin?
Tryptophan
What are the effects of niacin deficiency?
The 4 D’s: Diarrhea, dermatitis, dementia, and death
What are some signs of niacin toxicity?
A niacin flush is a sign. May lead to liver damage.
What are some potential health benefits from overdoes of niacin?
Lowers LDL cholesterol and triglycerides
Increases HDL cholesterol.
What are the functions of biotin?
- Critical in the TCA cycle by delivering carbon molecules to pyruvate molecules to form oxaloacetate.
- Coenzyme for the breakdown of fatty acids and amino acids
What foods are great sources of biotin?
Eggs
What is the function of Pantothenic acid?
Forms coenzyme A which in turn forms Acetyl CoA
What processes readily destroy pantothenic acid?
Freezing, canning, and refining processes.
What are the three forms of Vitamin B6?
Pyridoxal, pyridoxine, and pyridoxamine
What is the function of Vitamin B6?
Part of the coenzyme that aids in transamination and deamination to aid in protein metabolism, as well as carb and fatty acid metabolism.
Where is Vitamin B6 stored that is unique to the vitamin?
Stored in muscle tissue.
Is folacin (folate) a polyglutamate or a monoglutamate?
Polyglutamate
Is folacin (folate) naturally occurring or is it synthetic?
Natural
Why is folic acid easier to absorb than folate?
Because the folate is a polyglutamate, it has to get broken down into monogluatamate whereas folic acid is already a monoglutamate.
What does it mean if a folate molecule is “active”?
A methyl group was taken by a Vitamin B12 molecule. Both are left as active molecules and ready to be used.
What vitamin does folate have the ability to activate?
Vitamin B12
What is the name of folate’s coenzyme?
Tetrahydrafolate
What processes is tetrahydrafolate affiliated with?
Converts vitamin B12 to coenzyme form
Regenerates methionine from homocysteine
Synthesizes DNA
How is folate disposed of?
-Secreted by the lover into bile
What individuals are at risk for folate deficiency?
-Pregnant women
What does folate deficiency do to infants in pregnant women?
- Can lead to neural tube defects (anencephaly)
- Can also lead to Spina Bifida
How does folate protect against heart disease?
Lowers homocysteine levels
How does folate deficiency lead to macrocytic cell anemia?
Lack of folate lets DNA break down, but the production of RNA continues and makes the cell swell. This large cell might stay within the blood cell which is not healthy.
What types of foods are rich in folate?
Enriched grains
Leafy greens
Legumes
Folate is dependent on what other vitamin?
Vitamin B12
Vitamin B12 is dependent on what other vitamin?
Folate
What are the two main functions of vitamin B12?
- Regeneration of methionine
- Synthesis of DNA and RNA
Where is vitamin B12 found in nature?
ONLY found in animal products. Non-animal products have to be enriched.
Summarize Vitamin B12 digestion in the stomach.
Hydrochloric acid denatures protein. Pepsin comes in and starts breaking peptide bonds which releases B12. Intrinsic factor gets released.
Summarize Vit. B12 digestion in the small intestine.
Intrinsic factor binds with the B12. The pair then goes and binds to receptors in the ileum. This is where absorption occurs.
Why are elderly individuals at risk for Vit B12 deficiency?
B/c the elderly have limited secretion of HCl and if the HCl can’t break the peptide bonds then pepsin can’t can’t get to the bonds and intrinsic factor can’t be signaled to get released.
What groups of individuals are susceptible to Vit B12 deficiency?
Elderly
Vegans
What are the adverse effects of too much B12?
No adverse effects. No UL.
