Dictionary

doctors’ symbol See Aesculapius.

doctor In a medical context, any medical professional with an MD, a PhD, or any other doctoral degree. The term doctor is quite unspecific. A doctor may, for example, be a physician, psychologist, biomedical scientist, dentist, or veterinarian. In a nonmedical context, a professor of history might be addressed as doctor, an eminent theologian might…

DOB Date of birth, an abbreviation that is frequently used in medical charting.

do not resuscitate A directive to not attempt mechanical or manual resuscitation if the patient stops breathing. Abbreviated DNR. See also advance directive.

D.O. Doctor of Osteopathy, an osteopathic physician. See also osteopath; osteopathy.

DNR Do not resuscitate.

DNA sequence The precise ordering of the bases (A, T, G, C) from which DNA is composed. Base pairs form naturally only between A and T and between G and C, so the base sequence of each single strand of DNA can be simply deduced from that of its partner strand. The DNA nucleotide code…

DNA replication A complex process whereby the “parent” strands of DNA in the double helix are separated, and each one is copied to produce a new (daughter) strand. This process is said to be “semiconservative” because one strand from each parent is conserved and remains intact after replication has taken place.

DNA repair pathway The sequence of steps in the repair of DNA. Each step is governed by an enzyme.

DNA repair gene A gene that is engaged in DNA repair. When a DNA repair gene is altered, mutations pile up throughout the DNA.

DNA repair The process by which a cell uses a series of special enzymes to repair mutations (changes) in DNA and restore the DNA to its original state. The DNA is constantly mutating and being repaired. This repair process is controlled by special genes. A mutation in a DNA repair gene can cripple the repair…

DNA polymerase An enzyme that catalyzes (speeds) the polymerization of DNA. DNA polymerase uses preexisting nucleic acid templates and assembles the DNA from deoxyribonucleotides.