Nutrition Chapter 7 Vocab

Coenzymes

A small molecule that works with an enzyme to promote the enzyme's activity. Many ________ have B vitamins as part of their structure.

Thiamin

A B vitamin involved in the body's use of fuels. B1

Beriberi

The thiamin deficiency disease, characterized by loss of sensation in the hands and feet, muscular weakness, advancing paralysis, and abnormal heart action.

Riboflavin

A B vitamin active in the body's energy releasing mechanisms. B2

Niacin

A B vitamin needed in energy metabolism. can be eatin preformed or made in the body from tryptophan one of the amino acids. other forms are nicotinic acid, ______amide, and nicotinamide.

Pellagra

The niacin deficiency disease. symptoms include the 4 D'sDiarrheaDementiaDermatitisDeath

Niacin Equivalents (NE)

The amount of niacin present in food, including the niacin that can theoretically be made from its precursor tryptophan and is present in the food.

Folate

A B vitamin that acts as part of a coenzyme important in the manufacture of new cells. the form added to foods and supplements is ___ic acid.

Neural tube defects (NTD)

abnormalities of the brain and spinal cord apparent at the birth and associated with low folate intake in women before and during pregnancy. the neural tube is the earliest brain and spinal cord structure formed during gestation.

Beta-carotene

an orange pigment with antioxidant activity; a vitamin A precursor made by plants and stored in human fat tissue.

Retinol

one of the active forms of vitamin A made from beta-carotene in animal and human bodies; an antioxidant nutrient. Other active forms are retinal and ___oic acid.

Retina

the layer of light sensitive nerve cells lining the back of the inside of the eye.

Cornea

the hard, transparent membrane covering the outside of the eye.

Rhodopsin

the light sensitive pigment of the cells in the retina; it contains vitamin A. (opsin means "visual protein")

Night blindness

slow recovery of vision after exposure to flashes of bright light at night; an early symptom of vitamin A deficiency.

Keratin

the normal protein of hair and nails.

Keratinization

accumulation of keratin in a tissue; a sign of vitamin A deficiency.

Xerosis

drying of the cornea; a symptom of vitamin A deficiency.

Xerophthalmia

progressive hardening of the cornea of the eye in advanced vitamin A deficiency that can lead to blindness (xero means "dry"; opthalm means "eye").

Epithelial tissue

the layers of the body that serve as selective barriers to environmental factors. Examples are the cornea, the skin, the repiratory tract lining, and the lining of the digestive tract.

Cell differentiation

the process by which immature cells are stimulated to mature and gain the ability to perform functions characteristic of their cell type.

Carotenoid

a member of a group of pigments in foods that range in color from light yellow to reddish orange and are chemical relatives of beta-carotene. many have a degree of vitamin A activity in the body.

Macular degeneration

a common, progressive loss of function of the part of the retina that is most crucial to focused vision. This degeneration often leads to blindness.

Dietary antioxidants

compounds typically found in plant foods that significantly decrease the adverse effects of oxidation on living tissues. the major antioxidant vitamins are vitamin E, C, and beta-carotene. many phytochemicals are also antioxidants.

Retinol activity equivalents (RAE)

a new measure of the vitamin A activity of beta-carotene and other vitamin A precursors that reflects the amount of retinol that the body will derive from a food containing vitamin A precursor compounds.

IU (international units)

a measure of fat-soluble vitamin activity sometimes used in food composition tables and on supplement labels.

Rickets

the vitamin D deficiency disease in children; characterized by abnormal growth of bone and manifested in bowed legs or knock knees, outward bowed chest, and knobs on the ribs.

Osteomalacia

the adult expression of vitamin D deficiency disease, characterized by an overabundance of unmineralized bone protein (osteo means "bone", mal means "bad"). symptoms include bending of the spine and bowing of the legs.

Osteoporosis

a weakening of bone mineral structures that occurs commonly with advancing age.

Tocopherol

a kind of alcohol. the active form of vitamin E is alpha ______.

Free radicals

atoms or molecules with one or more unpaired electrons that make the atom or molecule unstable and highly reactive.

Erythrocyte hemolysis

rupture o the red blood cells that can be caused by vitamin E deficiency (erythro means "red", cyte means "cell", memo means "blood", lysis means "breaking"). the anemia produced by the condition is hemolytic anemia.

Jaundice

yellowing of the skin due to spillover of the bile pigment bilirubin from the liver into the general circulation.

Scurvy

the vitamin C deficiency disease.

Ascorbic acid

one of the active forms of vitamin C; an antioxidant nutrient. (another form of active vitamin C is dehydroascorbic acid)

Collagen

the chief protein of most connective tissues, including scars, ligaments, and tendons, and the underlying matrix on which bones and teeth are built.

Prooxidant

a compound that triggers reactions involving oxygen.

Subclinical deficiency

a nutrient deficiency that has no outward clinical symptoms. also called marginal deficiency.

Dietary folate equivalent (DFE)

a unit of measure expressing the amount of folate available to the body from naturally occurring sources. the measure mathematically equalizes the difference in absorption between less absorbable food folate and high absorbable synthetic folate added to enriched foods and found in supplements.

Vitamin B 12

a B vitamin that helps to convert folate to its active form and also helps maintain the sheath around nerve cells. its scientific name is cyanocobalamin.

Intrinsic factor

a factor found inside a system. the ________ ______ necessary to prevent pernicious anemia is now known to be a compound that helps in the absorption of vitamin B 12.

Pernicious anemia

a vitamin B12 deficiency disease, caused by lack of intrinsic factor and characterized by large, immature red blood cells and damage to the nervous system (pernicious means "highly injurious or destructive")

Vitamin B6

a B vitamin needed in protein metabolism. its three active forms are pyridoxine, pyridoxal, and pyridoxamine.

Serotonin

a neurotransmitter important in sleep regulation, appetite control, and mood regulation,among other roles. _______ is synthesized in the body from the amino acid tryptophan with the help of vitamin B6.

Biotin

a B vitamin; a coenzyme necessary for fat synthesis and other metabolic reactions.

Pantothenic acid

a B vitamin and part of a critical coenzyme needed in energy metabolism, among other roles.

Choline

a nutrient used to make the phospholipid lecithin and other molecules.

Carnitine

a nonessential nutrient that functions in cellular activities.

Inositol

a nonessential nutrient found in cell membranes.

Lipoic acid

a nonessential nutrient.

Vitamins

organic compounds that are vital to life and indispensable to body functions but are needed only in minute amounts; noncaloric essential nutrients.

Precursors

compounds that can be converted into active vitamins. also called provitamins.