MCB 3020 Lecture Notes - Lecture 12: Neoplasm, Metastasis, Anaplasia
Document Summary
Chapter 6: viruses and other acellular infection agents. Lysogenic conversion: temperate phage changes phenotype of its host. Phage may express pathogenic toxin or enzyme: two advantages to lysogeny for virus. Phage remains viable but may not replicate. Multiplicity of infection ensures survival of host cell: under appropriate conditions infected bacteria will lyse and release phage particles. Occurs when conditions in the cell cause the prophage to initiate synthesis of new phage particles, a process called induction. Archaeal viruses: may be lytic or temperate, most discovered so far are temperate by unknown mechanisms. Infection in eukaryotic cells: cytocidal infection results in cell death through lysis, persistent infections may last years, cytopathic effects (cpes) Benign tumors remain in place: neoplasia. Abnormal new cell growth and reproduction due to loss of regulation: anaplasia reversion to a more primitive or less differentiated state, metastasis. Carcinogenesis: complex, multistep process, often involves oncogenes.
