De novo synthesis
the formation of an essential molecule from simple precursor molecules.
the removal of necrotic or infected tissue or foreign material from a wound.
a chemical reaction involving the removal of a carboxyl (-COOH) group from a compound.
significant impairment of intellectual abilities, such as attention, orientation, memory, judgment or language. By definition, dementia is not due to major depression or psychosis. Alzheimer’s disease is the most common cause of dementia in older adults.
a branched extension of a neuron that receives signals from other neurons.
an immune cell that functions in antigen presentation and activation of T lymphocytes. Dendritic cells have a branched morphology that resembles dendrites of a neuron.
cavities or holes in the outer two layers of a tooth—the enamel and the dentin. Dental caries are caused by bacteria, which metabolize carbohydrates (sugars) to form organic acids that dissolve tooth enamel.
a nutritional study designed to determine the requirement for a specific nutrient. Generally, subjects are placed on a diet designed to deplete them of a specific nutrient over time. Once depletion is achieved, gradually increasing amounts of the nutrient under study are added to the diet until the individual shows evidence of sufficiency or repletion.
inflammation of the skin. This term is often used to describe a skin rash.
any skin disease, especially one not characterized by inflammation.
the layers of skin below the epidermis that support the epidermis in both structure and function. Although the majority of cells in this layer are fibroblasts supported by a collagen network, blood vessels, immune cells, and adipose tissue are also found in the dermis.
dual energy X-ray absorptiometry. A precise instrument that uses the energy from very small doses of X-rays to determine bone mineral density (BMD) and to diagnose and follow the treatment of osteoporosis.
a chronic metabolic disease, characterized by abnormally high blood glucose (sugar) levels, resulting from the inability of the body to produce or respond to insulin. Type 1 diabetes mellitus, formerly known as insulin-dependent or juvenile-onset diabetes, is usually the result of autoimmune destruction of the insulin secreting ß-cells of the pancreas. The most common form of diabetes is type 2 diabetes mellitus, formerly known as noninsulin-dependent or adult onset diabetes, which develops when the tissues of the body become less sensitive to insulin secreted by the pancreas.
a potentially life-threatening condition characterized by ketosis (elevated levels of ketone bodies in the blood) and acidosis (increased acidity of the blood). Ketoacidosis occurs when diabetes is not adequately controlled.
a medical procedure to filter waste products from the blood. Dialysis is needed to perform the work of the kidneys if they can no longer function effectively. Two types of dialysis are hemodialysis and peritoneal dialysis.
Diastolic blood pressure
the lowest arterial blood pressure during the heart beat cycle, and the second number in a blood pressure reading (e.g., 120/80).
changes in a cell resulting in its specialization for specific functions, such as those of a nerve cell. In general, differentiation of cells leads to a decrease in proliferation.
a passive process, in which particles in solution move from a region of higher concentration to one of lower concentration.
a complex of two molecules, usually proteins. Heterodimers are complexes of two different molecules, while homodimers are complexes of two of the same molecule.
an agent that increases the formation of urine by the kidneys, resulting in water loss from the individual using the diuretic.
inflammation or infection of diverticula in the colon (see diverticulosis), characterized by abdominal pain, fever, and constipation.
a condition characterized by the formation of small pouches (diverticula) in the colon. Although most people with diverticulosis experience no symptoms, about 15-20% may develop pain or inflammation, known as diverticulitis.
deoxyribonucleic acid; a double-stranded nucleic acid composed of many nucleotides. The nucleotides in DNA are each composed of a nitrogen-containing base (adenine, guanine, cytosine, or thymine), a five-carbon sugar (deoxyribose), and a phosphate group. The sequence of bases in DNA encodes the genetic information required to synthesize proteins.
the complex formed when a chemical forms a covalent bond with DNA.
a trait that is expressed when only one copy of the gene responsible for the trait is present.
refers to a study in which neither the investigators administering the treatment nor the participants know which participants are receiving the experimental treatment and which are receiving the placebo.
dietary reference intake. Refers to a set of at least four nutrient-based reference values (RDA, AI, UL, EAR), each with a specific use in defining recommended dietary intake levels for individual nutrients in the US. The DRIs are determined by expert panels appointed by the Food and Nutrition Board of the Institute of Medicine.
daily value. Refers to the dietary reference values required as the basis for declaring nutrient content on all products regulated by the US Food and Drug Administration (FDA), including nutritional supplements. The DVs for vitamins and minerals reflect the National Academy of Sciences’ 1968 RDAs, and do not reflect the most up-to-date Dietary Reference Intakes.
impaired control of voluntary movement. Dyskinesia is sometimes a side effect of long-term use of antipsychotic medications.
a disorder of lipoprotein metabolism.
Back to top
estimated average requirement; a nutrient intake value that is estimated to meet the requirement of half of the healthy individuals in a particular life stage and gender group.
a diagnostic test that uses ultrasound to make images of the heart. It can be used to assess the health of the valves and chambers of the heart, as well as to measure cardiac output.
seizures in a woman caused by pregnancy-induced hypertension; a significant cause of maternal mortality.
an epidemiological study that examines the relationships between exposures and disease rates in a series of populations (e.g., different countries). Ecological studies often rely on published statistics, such as food disappearance data or disease-specific death rates.
swelling; accumulation of excessive fluid in subcutaneous tissues (beneath the skin).
a chemical messenger derived from a 20-carbon polyunsaturated fatty acid, such as arachidonic acid and eicosapentaenoic acid. Eicosanoids play critical roles in immune and inflammatory responses.
a flexible structural protein similar to collagen; elastin is found in the dermal layer of skin and other parts of the body.
a recording of the electrical activity of the heart, used to diagnose cardiac arrhythmias, myocardial ischemia and myocardial infarction.
a recording of the electrical activity of the brain, used to diagnose neurological conditions like seizure disorders (epilepsy).
ionized (dissociated into positive and negative ions) salts in the body fluids. Major electrolytes in the body include sodium, potassium, magnesium, calcium, chloride, bicarbonate, and phosphate.
a stable atomic particle with a negative charge.
Electron transport chain
a group of electron carriers in mitochondria that transport electrons to and from each other in a sequence, in order to generate ATP.
one of the 103 chemical substances that cannot be divided into simpler substances by chemical means. For example, hydrogen, magnesium, lead, and uranium are all chemical elements. Trace elements are chemical elements that are required in very small (trace) amounts in the diet to maintain health. For example, copper, selenium, and iodine are considered trace elements.
a chronic obstructive pulmonary (lung) disease, characterized by damage to the small air sacs (alveoli) and difficulty breathing. Damage to the alveoli decreases their elasticity and results in hyperinflation of the lungs, which impairs gas exchange. Smoking is the most common cause of emphysema.
the hard, white, outermost layer of a tooth.
the glands and parts of glands that secrete hormones that integrate and control the body’s metabolic activity. Endocrine glands include the pituitary, thyroid, parathyroids, adrenals, pancreas, ovaries, and testes.
A type of cellular uptake that involves invagination of the cell membrane at the site of ligand binding followed by internalization of the substance inside a membrane-bound vesicle.
arising from within the body. Endogenous synthesis refers to the synthesis of a compound by the body.
the inner lining of the uterus.
arterial vasodilation resulting from the production of nitric oxide in the vascular endothelium.
toxins released by certain bacteria.
a cell that lines the luminal (inner) surface of the intestine.
a biological catalyst; that is, a substance that increases the speed of a chemical reaction without being changed in the overall process. Enzymes are vitally important to the regulation of the chemistry of cells and organisms.
a study examining disease occurrence in a human population.
the outer layers of skin above the dermis. The epidermis consists of overlapping layers of keratinocytes in various stages of development, eventually forming the barrier that protects underlying cell layers from the environment.
a system of tubules emerging from the testes, which serves as a storage site for sperm during their maturation.
also known as seizure disorder. Individuals with epilepsy experience seizures, which are the result of uncontrolled electrical activity in the brain. A seizure may cause a physical convulsion, minor physical signs, thought disturbances, or a combination of symptoms.
layer of cells that lines a body cavity or covers an external surface of the body.
reddening of the skin; often used as an indice of inflammation caused by ultraviolet exposure.
red blood cell.
relating to erythrocytes.
a hormone produced by specialized cells in the kidneys that stimulates the bone marrow to increase the production of red blood cells. Recombinant erythropoietin is used to treat anemia in patients with end stage renal failure.
the portion of the gastrointestinal tract that connects the throat (pharynx) to the stomach.
the product of a reaction between a carboxylic acid and an alcohol that involves the elimination of water. For example a cholesterol ester is the product of a reaction between a fatty acid and cholesterol.
a hormone that binds to estrogen receptors in the nuclei of cells and promotes the transcription of estrogen-responsive genes. Endogenous estrogens are steroid hormones produced by body. Exogenous estrogens are synthetic or natural compounds that have estrogenic activity (i.e., bind the estrogen receptor and promote estrogen-responsive gene transcription).
the causes or origin of a disease.
the toxicity that results from the continuous stimulation of nerve cells by neurotransmitters.
the elimination of wastes from blood or tissues.
a set of mental processes that helps connect past experience with present action. Executive functions include planning, organizing, strategizing, remembering details, and managing time and space.
Extracellular fluid (ECF)
the volume of body fluid excluding that in cells. ECF includes the fluid in blood vessels (plasma) and fluid between cells (interstitial fluid).
Back to top
Familial adenomatous polyposis
a hereditary syndrome characterized by the formation of many polyps in the colon and rectum, some of which may develop into colorectal cancer.
an organic acid molecule consisting of a chain of carbon molecules and a carboxylic acid (-COOH) group. Fatty acids are found in fats, oils, and as components of a number of essential lipids, such as phospholipids and triglycerides. Fatty acids can be burned by the body for energy.
a portion of the thighbone (femur). The femoral neck is found near the hip, at the base of the head of femur, which makes up the ball of the hip joint. Fractures of the femoral neck sometimes occur in individuals with osteoporosis.
an anaerobic process that involves the breakdown of dietary components to yield energy.
a cell that secretes extracellular matrix proteins, such as collagen, which give skin its structure. These cells are mostly found in the dermis and connective tissue.
Fibrocystic breast changes (FCC)
a benign (noncancerous) condition of the breasts, characterized by lumpiness and discomfort in one or both breasts.
a phenomenon of drug metabolism whereby the concentration of a drug is greatly reduced before it reaches the systemic circulation due to action from the gastrointestinal tract and liver.
Food frequency questionnaire
a method of dietary assessment in which study participants are given a validated list of food and beverages and asked to report the frequency and portion size consumed over a given period of time.
Forced expiratory volume (FEV1)
the volume of air that can be expelled during the first second of a forced expiration. FEV1 is used to assess pulmonary (lung) function.
the addition of nutrients to foods to prevent or correct a nutritional deficiency, to balance the total nutrient profile of food, or to restore nutrients lost in processing.
a break in a bone or cartilage, often but not always the result of trauma.
a very reactive atom or molecule typically possessing a single unpaired electron.
describes a group of circulating proteins that have become irreversibly bound to glucose. Fructosamine assays provide information about blood glucose control two to three weeks prior to sample collection.
a very sweet six-carbon sugar abundant in plants. Fructose is increasingly common in sweeteners such as high-fructose corn syrup.