Midterm Micro

Function vs. nutrient

Transamination reactions. - Vitamin B6 One-Carbon Metabolism. - Folate Synthesis of phospholipids and methyl donor. - Choline Antioxidant. - Vitamin E Anti-hemorrhagic factor. - Vitamin K

What form of tocopherol shows vitamin E activity in the human body? Select one: a. Beta b. Delta c. Alpha d. Gamma

c. Alpha

Of the following, which would most readily induce a vitamin K deficiency? Select one: a. Achlorhydria b. Presence of oxalic acid in food c. Antibiotic therapy d. Insufficient intake of green leafy vegetables

c. Antibiotic therapy

Which of the following features do vitamins C and E share? Select one: a. Both require bile for absorption b. Neither participates in protein synthesis c. Both function as antioxidants d. Neither is affected by the processing of foods

c. Both function as antioxidants

Among the following, which would be the best source of niacin equivalents? Select one: a. Strawberries b. Broccoli c. Chicken d. Milk

c. Chicken

Which of the following is a feature of vitamin E? Select one: a. Toxicity symptoms include bone abnormalities b. Functions as a hormone-like substance c. Deficiencies occur from inability to absorb dietary lipids d. Important food sources include enriched breads and pasta

c. Deficiencies occur from inability to absorb dietary lipids

*Which of the following functions is shared by beta-carotene and vitamin E? Select one: a. Prevention of hemolytic anemia b. Prevention of keratinization c. Inhibition of oxidation d. Inhibition of bone calcium loss

c. Inhibition of oxidation

*What is the function of intrinsic factor in vitamin B12 absorption? Select one: a. It acts as a cofactor for mucosal enzymes involved in absorption of the vitamin b. It acts as a storage protein for the vitamin within the intestinal epithelial cells c. It attaches to the vitamin, thereby allowing absorption from the small intestine d. It catalyzes release of the vitamin from its protein-bound form

c. It attaches to the vitamin, thereby allowing absorption from the small intestine

What vitamin deficiency disease appeared in people who had subsisted on a diet high in corn and low in protein? Select one: a. Wet beriberi b. Scurvy c. Pellagra d. Pernicious anemia

c. Pellagra

_______ is the form of Vitamin K found in foods. Select one: a. Menadione b. Menaquinone-7 (K2) c. Phylloquinone (K1) d. Quinine

c. Phylloquinone (K1)

Your sister Ellen has just joined the Peace Corps and will be working on ways to improve the nutritional status of children in Indonesia. Once there, she saw that many of the children and some adults suffer from night blindness. Which of the following foods should she recommend be incorporated into the Indonesian diet to help prevent future generations from developing this condition? Select one: a. Peanut butter b. Orange juice c. Sweet potato d. Powdered skim milk

c. Sweet potato

Which of the following are major sources of vitamin E in the diet? Select one: a. Milk and dairy products b. Meats c. Vegetable oils d. Citrus fruits

c. Vegetable oils

*Your brother Bob is a competitive body builder. His trainer suggested that he consume 4 egg white omelets per day. Bob remembers a warning about a possible vitamin deficiency from consuming too many egg whites and asks if he should follow the prescribed diet. Your reply to Bob is that he should NOT Select one: a. be concerned as long as he consumes both the yolk and whites of the eggs. b. follow the diet, since the avidin in the egg whites could bind to biotin and prevent its absorption. c. be concerned, because, when the eggs are cooked, the avidin protein is denatured, and thus does not pose a problem for deficiency disease. d. follow the diet, since the avidin in the egg whites could bind to niacin and prevent its absorption.

c. be concerned, because, when the eggs are cooked, the avidin protein is denatured, and thus does not pose a problem for deficiency disease.

The protein that requires ascorbic acid for its formation is Select one: a. albumin. b. keratin. c. collagen. d. hydroxyproline.

c. collagen.

All of the following are consequences of ingesting excess vitamin C supplements EXCEPT Select one: a. they appear safe at levels up to 2000 mg/day. b. they interfere with laboratory urine tests for the diagnosis of diabetes. c. they enhance the action of anticlotting medications. d. they frequently cause diarrhea.

c. they enhance the action of anticlotting medications.

Riboflavin is most easily destroyed when exposed to Select one: a. heat. b. alkali. c. ultraviolet light. d. acid.

c. ultraviolet light.

*Methylcobalamin is a coenzyme form of Select one: a. vitamin B6. b. niacin. c. vitamin B12. d. vitamin B1.

c. vitamin B12.

__________________ is the main form of choline in food and in the body. Select one: a. Sphingomyelin b. Free choline c. PtdCho (phosphatidylcholine) d. Betaine

c. PtdCho (phosphatidylcholine)

_______ of tocopherols consumed from foods is bioavailable. Select one: a. 75% b. 25% c. 50% d. 100%

c. 50%

Which lifestyle factors increase oxidant production and lower vitamin C levels (may INCREASE vitamin C requirements)? Select one: a. ETOH intake b. Obesity c. All choices are correct d. Smoking

c. All choices are correct

Anticoagulants, such as warfarin, inhibit _____ in the vitamin K cycle. Select one: a. Prothrombin Incorrect b. VKOR c. Gamma carboxylase d. Diaphorases

VKOR

Choline - Whole egg Folate - Spinach Biotin - Beef liver Vitamin K - Spinach Riboflavin - Beef liver

Vitamin E - Plant oils Thiamin - Pork Vitamin B12 - Clams Vitamin B6 - Beef Niacin - Beef liver

Retinol-binding protein is required to transport vitamin Select one: a. E. b. D. c. A. d. K.

c. Vitamin A.

T/F: Most B12 deficiencies are associated with poor dietary intake.

False

T/F: There is good evidence that dietary vitamin C, consumed in large amounts exceeding the RDA, protects against or treats the common cold.

False

What feature is shared by vitamins E and K? Select one: a. Both have strong antioxidant properties b. Neither is involved in bone development c. Supplements of either may interfere with anticlotting medications d. Deficiencies of either lead to anemia

Supplements of either may interfere with anticlotting medications

T/F: Fat-soluble vitamins are transported into enterocytes as part of micelles, similar to cholesterol.

True

T/F; ETOH is related to bioavailability and function of all of the B-vitamins.

True

Greg says that he usually eats 1 medium carrot every day to ensure that he's consuming enough vitamin A. Today he said he didn't eat any carrots and is worried that there is not enough vitamin A in his system. What would you say to Greg to allay his fear? Select one: a. "Don't worry; fat-soluble vitamins are stored in the body. It takes a lot longer than one day to develop any adverse effects." b. "Well, there isn't any vitamin A in carrots so you probably haven't consumed vitamin A for some time now." c. "As long as you eat some chicken tonight you will not develop chicken eyes." d. "Take a vitamin A supplement as soon as you can!"

a. "Don't worry; fat-soluble vitamins are stored in the body. It takes a lot longer than one day to develop any adverse effects."

*Which of the following is a characteristic of vitamin C and vitamin E? Select one: a. Both protect against LDL oxidation b. Neither reduces arterial inflammation c. Both act as prooxidants at physiological intakes d. Neither participates in regulating blood clotting

a. Both protect against LDL oxidation

John is looking to increase his dietary sources of vitamin C. However, he expresses a strong dislike for all citrus fruits. Which of the following shopping lists would you recommend? Select one: a. Brussels sprouts, broccoli, strawberries b. Banana, peanut butter, canned tuna fish c. Liver, yogurt, milk d. Whole grains, pork, fortified corn flakes

a. Brussels sprouts, broccoli, strawberries

What is the major carrier of the fat-soluble vitamins from the intestinal epithelial cell to the circulation? Select one: a. Chylomicrons b. Liposoluble binding proteins c. Cholesterol d. Albumin

a. Chylomicrons

A deficiency of which of the following vitamins results in accumulation of homocysteine in the blood? Select one: a. Folate b. Biotin c. Niacin d. Vitamin K

a. Folate

Which of the following describes an association between vitamin A and vision? Select one: a. Light causes retinal to shift from a cis to a trans configuration b. Retinol is the form bound to beta-carotene in the corneal membrane c. Pigment molecules in the retina are composed of a molecule of vitamin A bound to an omega-3 fatty acid d. Retinoic acid is the form required for synthesis of retinoblasts

a. Light causes retinal to shift from a cis to a trans configuration

Which of the following describes an event in the visual response process? Select one: a. Light energy strikes the retina and excites pigments to release retinal b. Visual pigments deep in the brain are excited by light transmitted through the retina c. Epithelial cells on the surface of the eye respond to light energy by transmitting opsin molecules along nerve pathways to the brain d. Light energy strikes the cornea and excites pigments to release retinoic acid

a. Light energy strikes the retina and excites pigments to release retinal

What tissue contains the majority of the body's store of vitamin A? Select one: a. Liver b. Retinal cells c. Adipose d. Intestinal mucosal cells

a. Liver

Which of the following foods is a very good source of vitamin A? Select one: a. Pumpkin pie b. Baked potato c. Whole-grain bread d. Corn

a. Pumpkin pie

Milk and milk products provide liberal amounts of which of the following vitamins? Select one: a. Riboflavin b. Pantothenic acid c. Folate d. Biotin

a. Riboflavin

Why are primary vitamin E deficiencies rarely observed in human beings? Select one: a. The vitamin is widespread in foods b. The vitamin can be synthesized by the body c. Most people take vitamin E supplements d. The vitamin is not essential

a. The vitamin is widespread in foods

Biotin is bound and made completely unavailable by _________, causing deficiency in humans if consumed over long periods of time (>25d). Select one: a. Raw egg white b. Milk c. Poultry d. Excess leucine

a. Raw egg white

______ can serve as a precursor for the synthesis of niacin-containing enzymes, and thus Niacin Equivalents (NE) can be calculated from the amount of this dietary constituent. Select one: a. Tryptophan b. Leucine c. Valine d. Lysine

a. Tryptophan

The percent bioavailability of a folate supplement taken on an empty stomach is Select one: a. 5. b. 100. c. 50. d. 25.

b. 100.

Nutritional resistance to anticoagulants results from: Select one: a. High vitamin C intake b. High vitamin K intake c. High cholesterol intake d. Low vitamin K intake

b. High vitamin K intake

How is vitamin E thought to play a role in reducing the risk of heart disease? Select one: a. It inhibits absorption of dietary cholesterol b. It slows oxidation of low-density lipoproteins c. It speeds removal of blood cholesterol by the liver d. It interferes with cholesterol synthesis by the liver

b. It slows oxidation of low-density lipoproteins

*What is the primary excretory route for the water-soluble vitamins? Select one: a. Bile b. Kidney c. Perspiration d. Intestine

b. Kidney

*The coenzyme FAD is formed from what vitamin? Select one: a. Choline b. Riboflavin c. Niacin d. Thiamine

b. Riboflavin

Why does vitamin A status depend on the person's protein status? Select one: a. Dietary protein ensures synthesis of the vitamin's GI tract transporter b. Transport of the vitamin within the body requires sufficient protein to synthesize retinol-binding protein c. Adequate protein intake is a marker for liberal intake of the vitamin

b. Transport of the vitamin within the body requires sufficient protein to synthesize retinol-binding protein

Why are strict vegetarians at risk of developing a vitamin B12 deficiency? Select one: a. Vegetarian diets inhibit absorption of the vitamin b. Vegetarian diets provide insufficient amounts of the vitamin c. The fiber content of vegetarian diets causes increased excretion of the vitamin d. The fiber content of vegetarian diets causes decreased storage by the liver

b. Vegetarian diets provide insufficient amounts of the vitamin

People with the condition known as iron overload may be adversely affected from taking supplements of Select one: a. niacin. b. ascorbic acid. c. retinol. d. cobalamin.

b. ascorbic acid.

A person seeking good sources of vitamin A would select all of the following EXCEPT Select one: a. apricots. b. bananas. c. liver. d. sweet potatoes.

b. bananas.

All of the following are features of vitamin K in nutrition EXCEPT Select one: a. infants frequently require a supplement at birth. b. gut microflora synthesis supplies sufficient amounts to meet the needs of most healthy adults. c. risk of deficiency is increased in people taking antibiotics for prolonged periods. d. good food sources are plants of the cabbage family.

b. gut microflora synthesis supplies sufficient amounts to meet the needs of most healthy adults.

Among the following water-soluble vitamins, a secondary deficiency would most likely be seen for Select one: a. thiamin. b. vitamin B12. c. vitamin C. d. biotin.

b. vitamin B12.

Pernicious anemia results from a deficiency of Select one: a. iron and copper. b. vitamin B12. c. selenium.

b. vitamin B12.

Vitamin C is transported by blood to tissues via ___________, which maintain physiological ascorbic acid levels in the blood. Select one: a. Leukocytes b. Sodium-dependent vitamin C transport proteins c. Zinc transporters d. Adrenal gland

b. Sodium-dependent vitamin C transport proteins

*What is the main function of pantothenic acid? Select one: a. Synthesis of carbohydrates b. Synthesis of CoA c. Synthesis of NAD d. Synthesis of fatty acids

b. Synthesis of CoA

People who smoke require additional vitamin C in the amount of Select one: a. 100 mg. b. 5 mg. c. 200 mg. d. 35 mg.

d. 35 mg.

Approximately what percentage of naturally occurring dietary folate is bioavailable? Select one: a. 80 b. 25 c. 10 d. 50

d. 50

*What organ stores the highest concentration of vitamin C? Select one: a. Liver b. Thyroid gland c. Muscle d. Adrenal glands

d. Adrenal glands

Which of the following food substances can be converted to vitamin A in the body? Select one: a. Chlorophyll b. Tryptophan c. Xanthophyll d. Beta-carotene

d. Beta-carotene

*What do beta-carotene and vitamin E have in common? Select one: a. Both are found in animal fats b. Neither is involved in synthesis of retinal c. Neither is involved in free radical control d. Both act as antioxidants

d. Both act as antioxidants

*Of the following foods, which would be the only source of vitamin B12? Select one: a. Cauliflower b. Whole-grain bread c. Pecans d. Hot dog

d. Hot dog

Knowing the role of vitamin K in the body, in what organ would you expect to find it in large quantities? Select one: a. Gallbladder b. Small intestine c. Pancreas d. Liver

d. Liver

*What food makes a significant contribution to vitamin C intakes in the U.S. population despite its modest vitamin C concentration? Select one: a. Breaded fish b. Organ meats c. Whole-grain cereals d. Potatoes

d. Potatoes

*The absorption of which of the following vitamins is most affected by the disorder atrophic gastritis? Select one: a. Pantothenic acid b. Choline c. Vitamin C d. Vitamin B12

d. Vitamin b12

Jennifer has just had a baby. When she brings Thomas home, she regales you with the details of her hospital stay. She mentions that shortly after the birth, Thomas received an intramuscular injection of vitamin K, and she wondered why this was done, as it made him cry. You explained that it Select one: a. was needed to promote good bone growth. b. was needed to prevent eye disease. c. protected the baby from lipid oxidation. d. prevented possible bleeding events.

d. prevented possible bleeding events.