NSC 308 Chapter 13

Which B-vitamins participate in energy metabolism?

• Niacin

• Thiamin

• Riboflavin

All B-vitamins form ______, which are small organic molecules that activate enzymes.

coenzymes

What are the two coenzyme forms of riboflavin?

• Flavin adenine dinucleotide

• Flavin mononucleotide

Thiamin is a key component required in the metabolism of the macronutrient ______.

carbohydrate

Identify three food sources of thiamin.

• Enriched flour

• Whole grains

• Pork

Which minerals participate in energy metabolism?

• Manganese

• Chromium

Coenzymes play an important role in metabolism because they ______.

aid in the function of activating enzymes

Which is the cofactor form of pantothenic acid?

Coenzyme A

A person experiencing peripheral neuropathy and weakness, muscle wasting pain and tenderness, and edema caused from lack of thiamin, is experiencing the deficiency disease known as ______.

beriberi

The B-vitamin required as a coenzyme (TPP) in the metabolism of carbohydrates and branched chain amino acids is ______.

thiamin

Functions of riboflavin include:

• participating in the formation of antioxidants.

• participating in the formation of other B-vitamins.

• energy-yielding metabolism.

Pork, enriched grains, and whole-grain products are excellent sources of ______.

thiamin

Which B-vitamins participate in energy metabolism?

• Niacin

• Riboflavin

• Thiamin

Food sources of riboflavin include ______.

• ready-to-eat cereal

• milk

• eggs

Beriberi is a deficiency disease caused by a lack of ______.

thiamin

Symptoms of ariboflavinosis include ______.

• seborrheic dermatitis

• stomatitis

• glossitis

Which B-vitamin is a component of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD)?

Riboflavin

Symptoms of a riboflavin deficiency include ______.

• inflamed mouth and tongue

• angular cheilitis

NAD and NADP are coenzyme forms of what B-vitamin?

Niacin

Cow's milk is an excellent source of ______.

riboflavin

A riboflavin deficiency usually occurs with a deficiency of several other B-vitamins because ______.

these nutrients often occur in the same foods

Which is true about riboflavin deficiency?

• People with alcoholism or very poor diets may be at risk of deficiency.

• Long-term use of phenobarbital increases risk of deficiency.

Which of the following foods is the best source of niacin?

Tuna, 3 oz

Niacin serves as a ______ participating in oxidation-reduction reactions.

coenzyme

Pellagra, the deficiency disease for niacin, is characterized by ______.

• dermatitis

• dementia

• diarrhea

Niacin-containing medications are ______ recommended to individuals with cardiovascular disease.

no longer

Which of the following is true about pantothenic acid?

• Pantothenic is from the Greek word pantothen meaning "from every side"

• Present in all body cells and supplied by a variety of foods

Rich dietary sources of niacin include ______.

• enriched flour products

• beef

• poultry

Which B-vitamin is essential in the formation of acetyl-CoA?

Pantothenic acid

Dementia, diarrhea, dermatitis, and death are symptoms of the deficiency disease known as ______.

pellagra

Sunflower seeds are a good source of which B-vitamin?

Pantothenic acid

Which B-vitamin was sometimes prescribed by physicians to increase HDL-cholesterol and lower triglyceride levels?

Niacin

A riboflavin deficiency usually occurs with a deficiency of several other B-vitamins because ______.

these nutrients often occur in the same foods

Identify symptoms of a pantothenic acid deficiency.

• Impaired muscle coordination

• Headache

• Fatigue

Which B-vitamin is used throughout the body in energy metabolism and is part of coenzyme A?

Pantothenic acid

What vitamin is needed by nearly all amino acids for metabolism?

Vitamin B-6

The coenzyme form of pantothenic acid (acetyl-CoA) participates in:

• release of energy from carbohydrates, fats, and proteins.

• fatty acid synthesis.

Vitamin B-6 coenzymes participate in ______ metabolic reaction(s).

numerous

Common food sources for pantothenic acid include ______.

• meat

• milk

The functions of vitamin B-6 include ______.

• folate metabolism

• homocysteine metabolism

• synthesis of nonessential amino acids

It is very rare to see a deficiency in ______; in fact, deficiencies have only been seen when experimentally induced.

pantothenic acid

What are the three compounds that make up the vitamin B-6 family?

• Pyridoxamine

• Pyridoxal

• Pyridoxine

Vitamin B-6 is required for the synthesis of several neurotransmitters such as:

• dopamine.

• serotonin.

• norepinephrine.

Almost all of the enzymatic reactions that vitamin B-6 participates in involve ______-containing compounds.

nitrogen

Which of the following is considered a function of vitamin B-6?

Supports immune function

A major role of the coenzyme form of vitamin B-6 (PLP) is to participate in ______ metabolism.

amino acid

Vitamin B-6 is lost in the refining of a grain but ______ added back during enrichment.

is not

Which B-vitamin is important in the synthesis of heme, a nitrogen-containing ring that is inserted into certain proteins to hold iron in place?

Vitamin B-6

Which are the functions of vitamin B-6?

• Helps support normal immune function

• May help prevent colon cancer

• Supports regulation of gene expression

A vitamin B-6 deficiency is ______ in North America.

rare

The term folic acid refers to the ______.

synthetic form of the vitamin found in supplements and fortified foods

Which of the following are good food sources of vitamin B-6?

• Poultry

• Meat

• Fish

The coenzymes of which B-vitamin are needed for the synthesis and maintenance of new cells?

Folate

Seborrheic dermatitis, microcytic hypochromic anemia, convulsions, depression, and confusion are symptoms of a ______ deficiency.

vitamin B-6

Folate coenzymes function in ______.

1-carbon transfer reactions

The generic name of the B-vitamin that is known for its role in DNA synthesis and amino acid metabolism, and that refers to the various forms of the vitamin found naturally in foods, is ______.

folate

The conversion of homocysteine to methionine requires the coenzyme forms of vitamin B-12 and ______.

folate

Folate is known for its role in ______.

• DNA synthesis

• amino acid metabolism

The coenzyme form of folate is required for the ______.

synthesis of DNA

The coenzyme form for folate is called ______.

tetrahydrofolic acid

The coenzyme form of folate accepts 1-carbon groups from amino acids and is responsible for the conversion of:

• histidine to glutamic acid.

• glycine to serine.

Which two B-vitamins' functions are closely linked?

Folate and vitamin B-12

Because methotrexate interferes with the metabolism of THFA ______. More than one answer may be correct.

• DNA synthesis is reduced

• the growth of cancer cells is halted

______, a B-vitamin, is required for normal cell division.

Folate

Why would consuming fresh or unprocessed fruits and vegetables contribute more folate?

Folate is destroyed by heat.

The water-soluble vitamin deficiency that may lead to megaloblastic anemia is due to a lack of ______.

folate

The coenzyme form of which vitamin is required to recycle the folate coenzyme needed for DNA synthesis?

Vitamin B-12

The red blood cells of a folate-deficient person differ from a healthy person by ______.

• remaining in an immature form

• becoming very large

• retaining their nuclei

Methotrexate interferes with ______.

THFA metabolism

A folic acid deficiency during pregnancy can result in the development of ______.

neural tube defects

The coenzyme form of folate is required for the ______.

synthesis of DNA

A folate deficiency during pregnancy increases the risk for spina bifida and anencephaly because folate ______.

promotes the development of the neural tube

The highest folate content may be obtained from eating ______.

fresh fruits and vegetables

Symptoms of a folate deficiency include:

• megaloblastic anemia.

• persistent diarrhea.

What type of anemia occurs when large red blood cells are unable to divide due to a folate deficiency?

Megaloblastic

Neural tube defects in a fetus caused by folic acid deficiencies during pregnancy include:

• spina bifida.

• anencephaly.

Which vitamin has foods of animal origin as its only reliable food source and is the only vitamin that contains a mineral as part of its structure?

Vitamin B-12

All women of childbearing age should consume adequate amounts of folate because ______.

the neural tube closes before many women even know they are pregnant

Vitamin B-12 is required to reform the ______ coenzyme THFA.

folate

The best source of vitamin B-12 would be ______.

a hamburger

Pernicious anemia is related to inadequate ______ absorption.

vitamin B-12

A deficiency of which water-soluble vitamins may result in megaloblastic anemia?

• Folate

• Vitamin B-12

Which vitamin is also known as cobalamin?

Vitamin B-12

When vitamin B-12 is lacking:

• the symptoms of a folic acid deficiency develop.

• THFA levels decline.

Vitamin B-12 is found in ______ foods only.

animal

The deficiency disease for vitamin B-12 is called ______.

pernicious anemia

If a person has a vitamin B-12 deficiency for a prolonged period of time, they will most likely develop ______ anemia.

• megaloblastic

• macrocytic