What do you already know about bacteria? DNA What do you already know about bacteria?

Bacteria

Bacterial Cells No membrane- bound organelles Do contain ribosomes for making proteins Have a cell wall with peptidoglycan Much larger than viruses, but smaller than eukaryotes

Bacterial Genome Double-stranded circular DNA 1/1000th as much DNA as eukaryotes 100x as much as virus Densely packed in nucleoid region

Bacterial Reproduction Called binary fission Two identical daughter cells formed, but NOT BY MITOSIS

But Recombination Occurs Bacteria still change and evolve by: Mutations Transduction Transformation Conjugation

Mutations Still somewhat rare BUT bacteria multiply at extremely rapid rates, so mutations occur somewhat often If a mutation occurs, ALL FUTURE OFFSPRING will have it

Transformation The process of bacteria taking in foreign DNA E.Coli when treated with lots of calcium can be made to take in foreign DNA, a huge tool in biotechnology!

Transduction Every time a virus leaves a cell, it takes a little extra DNA with it This DNA can be transferred to new hosts

Plasmids Small, circular self- replicating segment of DNA in bacteria Not necessary for survival, but can provide benefits for bacteria Might also be ancestor of viruses?

Major Types of Plasmid R Plasmid – gives resistance to antibiotics F Plasmid – allows bacteria to pass along DNA via a pili – like a bacterial penis

Conjugation - Bacterial Sex One bacteria donates a plasmid to another Via the pillus Allows bacteria to pass along things such as resistance

F Plasmid

Treating Bacterial Infections Much easier than viruses Antibacterial agents can attack the bacteria, without affecting us Attack bacterial cell walls, protein synthesis, DNA synthesis, ribosomes etc. But bacteria evolve resistance!