Who will win the drugs race?
amino acid. The basic building block of protein. All amino acids contain an amino (NH2 ) end, a carboxyl end (COOH) and a side group (R). In proteins, amino acids are joined together when the NH2 group of one forms a bond with the COOH group of the adjacent amino acid. The side group is what distinguishes each of the amino acids from the others.
There are 20 common amino acids: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine.
anabolic steroids. Compounds that promote the growth or synthesis (anabolism) of tissue, especially muscle. More information can be found at What are anabolic steroids? (National Institute on Drug Abuse, USA).
creatine. A naturally occurring compound produced by the body, which combines with phosphate to form creatine phosphate. The combination of creatine and phosphate stores energy that can then be used for muscle contraction.
hormone. A substance produced in one part of the body and carried by the blood to another part of the body where it causes a response (eg, insulin, produced by the pancreas, that promotes the uptake of glucose by body cells). For more information see The hormones of the human (Kimball's Biology Pages, USA) and The hormones (Center for Bioenvironmental Research, Tulane and Xavier Universities, USA).
isotope. One of the different kinds of an atom of the same element. All atoms of an element have the same chemical properties, but the different isotopes have different weights. The different weights are because the isotopes have a different number of neutrons. For more information, see Isotopes (Carlton Comprehensive High School, Canada)
mass spectrometry. A method of determining the types, and relative amounts, of ions in a sample. In a mass spectrometer, atoms or molecules in a sample are ionised by an electric beam. The ions are accelerated by an electric field and then deflected by a powerful magnet. Different ions are deflected to different degrees, so the composition of the sample can be determined. More information can be found at An introduction to mass spectrometry (University of Leeds, UK).
peptide. A molecule consisting of a short chain of amino acids. Longer chains of amino acids are called proteins.
placebo. An imitation of a medical treatment. This can be an inactive substance (eg, a sugar pill) or some other form of treatment which simulates a medical treatment, but should have no physiological effect. A placebo is given to a person, often as an experimental control, to enable comparison with the effects of a real drug or treatment.
protein. A large molecule composed of a linear sequence of amino acids. This linear sequence is a protein's primary structure. Short sequences within the protein molecule can interact to form regular folds (eg, alpha helix and beta pleated sheet) called the secondary structure. Further folding from interaction between sites in the secondary structure forms the tertiary structure of the protein.
Proteins are essential to the structure and function of cells. They account for more than 50 per cent of the dry weight of most cells, and are involved in most cell processes. Examples of proteins include enzymes, collagen in tendons and ligaments and some hormones. More information can be found at Protein structure and diversity (Molecular Biology Notebook, Rothamsted Research, UK).
recombinant DNA. Genetically engineered DNA that is prepared in a laboratory by cutting up DNA molecules and splicing together specific DNA fragments. Usually the DNA that is combined is from more than one species. The spliced DNA can then be used to synthesise proteins. More information can be found at Speaking the language of recombinant DNA (Access Excellence, USA).
transferrin. A type of protein that acts as the vehicle for transporting iron between different sites in the body.
Page updated August 2006.