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- Carbohydrate
- carbohydrate (kär´bo-hì¹drât´), any member of a large class
of chemical compounds that includes sugars, starches, cellulose, and related compounds.
Carbohydrates are produced naturally by green plants from carbon dioxide and water (see PHOTOSYNTHESIS). Essential nutrients, they are the
human body’s main source of both quick and sustained energy. The three main classes
of carbohydrates are monosaccharides, which are the simple SUGARS, e.g., FRUCTOSE and
GLUCOSE; disaccharides, which are made up of two monosaccharide units and include LACTOSE,
MALTOSE, and SUCROSE; and polysaccharides, which are polymers with many monosaccharide
units and include CELLULOSE, GLYCOGEN, and STARCH. 1
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- Catabolism
- catabolism (ke-tàb¹e-lîz´em) noun The metabolic
breakdown of complex molecules into simpler ones, often resulting in a release of energy.
[CATA- + (META)BOLISM.] — cat´a·bol¹ic (kàt´e-bòl¹îk) adjective
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- Catecholamine
- catecholamine (kàt´î-ko¹le-mên´), any of several
structurally related compounds found in the body that help regulate the sympathetic
NERVOUS SYSTEM. They include EPINEPHRINE (or adrenaline), NOREPINEPHRINE, and
dopamine—substances that prepare the body to meet emergencies such as cold, fatigue,
and shock. Epinephrine and isoproterenol, a synthetic catecholamine, are used as drugs to
treat diseases such as EMPHYSEMA, BRONCHITIS, and ASTHMA. 1
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- Cellular Respiration
- cellular respiration noun The series of metabolic processes by
which living cells produce energy through the oxidation of organic substances. 1
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- Citric Acid Cycle
- see The Krebs Cycle
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- Chronic Fatigue Syndrome
- chronic fatigue syndrome, syndrome that begins with flu-like
symptoms followed by months or years of lethargy, weakness, and inability to concentrate.
Misdiagnosed as "imaginary" for nearly a century, it has had various names,
including the "yuppie flu" in the mid-1980s. Although many patients exhibit
signs of brain inflammation, hormonal deficits, immune system abnormalities, and viral
infections, the exact cause is unknown. 1
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- Clinical Trial
- clin·i·cal trial (klîn¹î-kel) adjective
- 1. Of, relating to, or connected with a trial at a clinic.
2. Involving or based on direct observation of the patient: a clinical
diagnosis.
3. Suggestive of a medical clinic; austere and antiseptic: a clinical style
of decor.
- — clin¹i·cal·ly adverb 2
- Cholesterol
- cholesterol (ke-lès¹te-rôl´), fat-related compound found in the tissues and
blood plasma of vertebrates. A STEROID, cholesterol is found in large concentrations in
the brain, spinal cord, and liver, and is a necessary component of cell membranes. It can
be obtained from animal products in the diet or synthesized in the liver. Cholesterol is
the major precursor of the synthesis of vitamin D and the various steroid HORMONES and can
crystallize in the GALL BLADDER to form gallstones. In the blood, cholesterol travels with
a protein in an organic compound called a LIPOPROTEIN. Low-density lipoproteins (LDLs)
convey cholesterol from the liver to the body's tissues, and high-density lipoproteins
(HDLs) convey cholesterol out of the blood stream for excretion. High levels of LDLs in
the blood, or low levels of HDLs, are associated with an increased risk of heart disease;
in atherosclerosis (see ARTERIOSCLEROSIS) deposits of cholesterol (mainly LDL cholesterol)
accumulate inside blood vessels. Reducing consumption of foods containing cholesterol and
saturated fat has been found to lower blood cholesterol levels; cholesterol levels can
also be reduced with drugs (e.g., lovastatin).1
- Coenzyme
- coenzyme (ko-èn¹zìm´), any of a group of relatively small
organic molecules that make up the non-protein portion of an ENZYME and without
which the enzyme is inactive. Coenzymes participate in chemical reactions
catalyzed by enzymes; although often structurally altered in the course of the reaction,
coenzymes are always restored to their original form. Notable coenzymes include ADENOSINE
TRIPHOSPHATE, important in the transfer of chemical energy, and VITAMINS, vital to a
variety of biochemical reactions in the body, including the Krebs cycle (see CITRIC ACID CYCLE). 1
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- Coenzyme A Abbr. CoA
- Coenzyme A (noun) A coenzyme present in all living cells that
functions as an acyl group carrier and is necessary for fatty acid synthesis and
oxidation, pyruvate oxidation, and other acetylation reactions. 2
- Cooley's Anemia
- Cooley's anemia (k¡¹lêz) noun A usually fatal form of thalassemia in
which normal hemoglobin is absent, characterized by severe anemia, enlargement of the
heart, liver, and spleen, and skeletal deformation.
- [After Thomas Benton Cooley (1871-1945), American physician.] 2
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