Biology 2581B Chapter Notes - Chapter 1: Girus, Archaea, Mimivirus
29 Mar 2017
School
Department
Course
Professor
Document Summary
Symbiosis of two prokaryotic cells at the origin of eukaryotes. Many are closely related to bacterial homologs and minority are archaeal origin. Archaeal genes in eukaryotes encode proteins involved in information processing (translation, transcription, replication) Bacterial genes encode operational proteins (metabolic enzymes and membrane transporters) Eukaryotes are archaebacterial genetic chimeras combinations of genes from 2 very different organisms. Invasion of one host cells by another, then degradation of invader/symbiont, invader becomes organelle (like mitochondria) Mitochondria retain common features with bacterial cells (small genome and translation system) Many bacterial genes were transferred from the genome of the endosymbiont to the eukaryotic nuclear genome during evolution of the mitochondria. One hypothesis holds that the host of the mitochondrial endosymbiont was a primitive eukaryotic cell (sometimes called an archaezoan) that possessed the signature structures of eukaryotes, including the nucleus, and was capable of phagocytosis.
