Mutations at specific HIV codons are associated with changes in the amino acid sequence of HIV's proteins and enzymes. Such mutations can cause HIV to become resistant to antiretroviral drugs. The phenomenon by which HIV and other disease-causing organisms become resistant to more than one drug after a single therapy. A double-stranded molecule that makes up the chromosomes in the center of a cell and that carries genetic information in the form of genes. Enzyme A cellular protein whose shape allows it to hold together several other molecules in close proximity to each other.
Enzymes also induce chemical reactions in other substances.
The best starting therapy for someone who has never received therapy before. Gene A unit of DNA in the chromosomes that determines the structure of a specific protein or enzyme. Genes regulate the metabolism of individual cells and the development and specialization of body cells and tissues. Genotype The genetic makeup of an individual organism, determined by the sequence of nucleotides in its genes. See also Phenotype .