Nutrition II Flashcards
What are the three dietary lipids? Which is the primary form of dietary lipids?
TAG, cholesterol and phytosterols
Triacylglycerols (>95%)
Palmitic acid and stearic acid are examples of what type of fatty acid?
Saturated
Are saturated fatty acids solids or liquids at room temperature?
Solid
What negative consequence is associated with saturated fatty acids?
Hypercholesterolemia
What are some foods that are high in saturated fatty acids?
animal and dairy fats, palm and coconut oil
Oleic acid is an example of what type of fatty acid?
Mono-unsaturated ( at least 12 carbons long, one double bond at C9)
What negative health consequences are associated with mono-unsaturated fats?
None: mono-unsaturated fats are not associated with hypercholesterolemia or decreased HDL
What are the two essential fatty acids? What type of fatty are they?
linoleic and alpha-linolenic acid
They are polyunsaturated fatty acids
What is the consistency of polyunsaturated fats at room temperature?
Liquid
How do polyunsaturated fats affect LDL and HDL?
They can lower both LDL and HDL (so bad/good affects)
What is essential fatty acid deficiency?
Deficiency in essential fatty acids (linoleic and alpha-linoleic acid)
Appears as scaly dermatitis
Name three omega-3 fatty acids
alpha-linoleic acid, EPA and DHA
Is it true that omega-3 fatty acids lowers your risk for CVD?
Yes- but only for people already at high risk
What are trans fats? How do they affect LDL and HDL?
hydrogenation turns liquid oils into solid fats (so unsaturated fats into solids)
They are associated with increased levels of LDL, Coronary heart disease and atherosclerosis, to the same degree or more than saturated fats
What are some common dietary sources of soluble fiber?
legumes, oats, some fruit, some vegetables, and nuts
How does soluble fiber affect cholesterol?
Soluble fibers is implicated in cholesterol lowering.
What are sources of insoluble fiber>
Potato skin, whole grains, wheat bran, some vegetables
What is the benefit of insoluble fiber?
Helps regulate bowel movements.
Which are the fat soluble vitamins?
A,D,E,K
What is another name for vitamin A?
Retinol
What is another name for vitamin D?
Cholecalciferol
What is another name for vitamin E?
Tocopherol
What is another name for vitamin K?
phylloquinone
Which are the water-soluble vitamins?
All the B vitamins + Vitamin C
What is another name for vitamin B1?
Thiamin
What is another name for vitamin B2?
Riboflavin
What is another name for vitamin B3?
Niacin
What is another name for vitamin B5?
Pantothenic acid
What is another name for vitamin B7?
Biotin
What is another name for vitamin B9?
Folic acid
What is another name for vitamin C?
Ascorbic Acid
What are the primary functions of water-soluble vitamins?
Coenzymes
What is beta-carotene?
Beta-carotene, found in many colored vegetables (like carrots) is a precursor for retinol (vitamin A)
What are the two metabolically active forms of vitamin A?
Retinol and Retinoic acid
What form of vitamin A is used as a prosthetic group for visual pigments? Which is used as a nuclear modulator of gene expression?
Prosthetic group of visual pigments: retinol
Nuclear modulator of gene expression: retinoic acid
Why is vitamin A critical for fetal growth?
Vitamin A, as retinoic acid, is critical for the differentiation and development of limbs during development
Where are carotenoids stored?
They can be stored anywhere, but mostly in the dermis. This is why you turn orange if you eat an absurd number of carrots.
What is an early sign of vitamin A deficiency?
Night blindness
What is the cardinal sign of a vitamin A deficiency?
Xerophthalmia- abnormal dryness of cornea and conjunctiva.
What are the symptoms of acute vitamin A toxicity?
nausea, vomiting, headache, peeling of skin
What is the cardinal sign of vitamin A toxicity?
bright red gingiva
What is the main function of vitamin D?
Maintain serum Ca2+ concentrations
Increase intestinal absorption, increase bone resorption, increase renal reabsorption
How does Vitamin D have an effect?
Vitamin D in its active form binds the Vitamin D receptor (a transcription factor) and regulates gene expression
What are the childhood and adult pathologies associated with vitamin D deficiency?
Childhood: Rickets- failure of appropriate mineral deposition in the epiphyseal cartilage
Adult: Osteomalacia- stimulated mobilization of calcium and phosphorus from bone to maintain serum concentrations
What populations are at risk for vitamin D deficiencies?
Dark colored skin- they absorb less UV light
People who don’t get any sun exposure (particularly breastfed infants)
What is the primary function of vitamin E?
Scavenger of free radicals and peroxyl radicals
What is the primary function of vitamin K?
Regulation of blood clotting protein synthesis
It functions as a coenzyme in carboxylation reactions
(Carboxylation enzyme deficiencies – think vitamin K)
What is the primary manifestation of vitamin K deficiencies?
Uncontrolled bleeding
Who is at highest risk for a vitamin K deficiency, and what is the result?
Newborns are often born with a vitamin K deficiency, and as a result, experience hemorrhaging.
Prophylactic vitamin K is given as a shot to newborns in nearly all developed countries
Thiamin/vitamin B1 is a coenzyme for which important metabolic enzyme?
Pyruvate dehydrogenase
The coenzyme is in the form of thiamin diphosphate (TPP)
All of the Beriberi syndromes are associated with a deficiency in what?
Vitamin B1- thiamin
What are the symptoms of dry beriberi?
Peripheral neuropathies, impairment of sensory motor and reflex functions
What are the symptoms of wet berberi?
Dry beriberi symptoms + cardiomegaly, congestive heart failure, edema
What are the symptoms of cerebral beriberi?
Wernicke’s encephalopathy. Mental confusion, bilateral 6th nerve paralysis
Why must you administer thiamin before giving glucose to a chronic alcoholic?
Because they may have a thiamin deficiency, in which case PDH function will be impaired and glycolysis will be inhibited. THis would lead to hyperglycemia
What is the first vitamin that should come to mind when you are dealing with chronic alcoholism?
Thiamin (B1)
Riboflavin, B2, has a third name- what is it?
FAD
Niacin (nicotinic acid, NAD and NADP) can be synthesized from which amino acid?
Tryptophan
Large doses of niacin can be used as a first pass drug for which chronic condition?
Hyperlipidemia
What are the 4 D’s of niacin deficiency?
Dermatitis, diarrhea, dementia and death
What three important enzymes require vitamin C as a cofactor?
Prolyl 4-hydroxylase, prolyl 3-hydroxylase and lysyl hydroxylase
These enzymes are all involved in collagen hydroxylation
What are the cardinal symptoms of scurvy?
Collagen formation deficiency leads to bleeding from gums and other mucus membranes, formation of spots on the skin
Folate is an important cofactor for reactions in what pathway?
Purine and pyrimidine biosynthesis
What two enzymes in particular are blocked by a folate deficiency?
Thymidylate synthase --> defective DNA synthesis Methionine Synthase (aka homocysteine methyltransferase)
What is another name for vitamin B12?
Cobalamin
What substance in the urine is indicative of a vitamin B12 deficiency?
MMA- methylmalonic acid
Hyperhomocysteinemia is commonly seen with deficiencies of what two vitamins?
Folate (B9) and Cobalamin (B12)
Pernicious anemia is caused by malabsorption of what vitamin?
B12
