Microbiology

Chapter 8 Key Terms Medical Microbiology Chromosomes: place where genetic “blueprint” is stored; double-stranded DNA; each cell usually contains 23 pairs Gene: unit of information encoded by DNA that can be expressed to form an RNA product Messenger RNA (mRNA): RNA products of most genes; RNA molecule that directs the synthesis of a specific protein Gene expression: use of gene information to make RNA and proteins Promoter: DNA control sequence containing information determining when a gene is expressed Operon: series of genes in a bacteria; all genes in operons are lined up and their expression (RNA synthesis) is controlled by a single promoter located in front of the first gene Structural gene: gene encoding a product, either RNA or protein Plasmids: smaller pieces of DNA that may enter of leave a bacterial cell without changing the species Horizontal gene transfer: transfer of a few genes from one organism to another Mutation: a base pair different from that of the preexisting parent cell Homologs: genes with shared ancestry and related function Semiconservative: in DNA replication; each daughter cell receives one original strand (parental strand) and one newly synthesized strand DNA Polymerase: enzyme that copies DNA