CBG Prokaryotes and Eukaryotes

Prokaryotes

• No nucleus
• Arose 3000 million years ago

Eukaryotes

• Nucleus
• Arose 1500 million years ago

• Circular chromosme
   
• Simple organelles
   
• Rotating flagellum
   
• Cell division by fission
   
• Small- 1μm- diffusuion limited

• Junk free genome
   
• DNA lacks histones (proteins that package and order the DNA into histones)
   
• One RNA polymerase using σ factor
   
•  tRNA_i^formylmet start codon
   
• 70S ribosomes

• Nucleus
   
• Linear chromosomes
   
• Endomembranes
   
• Endosymbionts (mitochondria and plastids)
   
• Cytoskeleton and 9+2 flagella
   
• Cell division by mitosis
   
• 100 μm 

• Genome contains 'junk'
   
• DNA bound by histones into nucleosomes
   
• Three RNA polymerases using TBP
   
• tRNA_i^met  start codon
   
• 80s ribosomes

rDNA is the DNA that encodes rRNA. These genes tend to be highly conserved, they mutate slowly, as they are essential to the cell.

• The prokaryotes are paraphyletic
• Eukaryotes and archaea are sister groups
• Bacteria is the outgroup

• Eukaryotes in a bacteria's clothing

They have:

Prokaryotic cell structure:

• No nucleus
• No endsosymbionts
• No cytoskleton
• Circular chromosomes

Eukaryotic molecular biology 

•  Histone-bound DNA
• tRNA^met  start codon
• RNA polymerase uses Tata binding protein

Core information processing genes more similar to eukaryotes, metabolism genes are more closely related to bacteria