Chapter: 17 Viruses Overview: A Borrowed Life ? A virus is an infectious particle consisting of little more than genes packaged into a protein coat ? Viruses lead ?a kind of borrowed life?, existing in a shady area between life-forms and chemicals. ? Viruses called bacteriophages can infect and set in motion a genetic takeover of bacteria, such as Escherichia coli. ? A virus consists of a nucleic acid surrounded by a protein coat. ? Virus lack the metabolic machinery found in a cell, thus they can?t reproduce or carry out metabolism. Concept 17.1 A virus consist of a nucleic acid surrounded by a protein coat ? Virus smaller than a ribosome and even the largest virus is barely visible under light Microscope ? Some viruses can be crystalized