BIOL 2020 Lecture Notes - Electron Acceptor, Craig Venter, Nitrogen Fixation
28 Mar 2014
School
Department
Course
Professor
Document Summary
Eukaryotes: cells that contain membrane bound organelles (nucleus, mitochondria, etc. ) Prokaryotes: cells that do not contain any membrane bound organelles. Do have some internal membranes but not surrounding organelles. Every life form has dna as its genetic material and has a membrane. Genetic code is very similar between the 2 cell types. Was a common ancestor (not sure when that happened) think it"s 2. 5 billion years old - planet earth is 4. 6 billion years old. Genetic tree - all organisms have been sequenced - based on ribosomal dna sequence. 3 major groups - bacteria (eubacteria), archaea (archeabacteria), eucarya. Bacteria had a common ancestor with both other cells - when looked at archaea, their sequences are closer to eucarya than they were to bacteria. Live in unusual environments (hot water), high salt concentration etc. To give them that ability they have different lipids, different membranes. When look with better equipment that we have today they found 20 amino acids.
