BACTERIA

Salmonella spp.

MRSA

Escherichia coli

Prokaryotes vs Eukaryotes• There are two basic types of cells: prokaryote and

eukaryote.• Plants, animals and fungi are eukaryotes: meaning they

have a true nucleus. • Prokaryotes are single-celled organisms. All bacteria are

prokaryotes. • They are the smallest, simplest organisms.

Eubacteria• This group includes the traditional bacteria and is the

largest of the two.

Bacteria are everywhere!• They are found in nearly every habitat studied, including

some that no other organism is able to withstand

General Structure of a Bacterium• Bacteria have : • a cell wall• a cell membrane • no membrane-bound

organelles such as a nucleus, mitochondria, chloroplasts, Golgi apparatus, or ER.

Movement: Cilia and Flagella• Some bacteria are able to move using special cell

structures called cilia and flagella.• Cilia are hair like• Flagella are tail-like• By repetitive beating (like a bending motion), they cause

the cell to move. Think of oars in a boat.

Bacterial shapes• Cocci – spherical

• Diplococci – pair• Streptococci - chain

•  Bacilli - rod-shaped• Spirochete – spiral

Asexual reproduction: Fission

• Prokaryotes reproduce by simply splitting in two in a process called binary fission.

• The DNA is copied and the cell divides into two identical cells.

Sexual reproduction: Conjugation• Sexual reproduction combines genes from two different individuals and increases variation.

•  Conjugation - Two cells join briefly and one cell donates some DNA (called a plasmid) to the other one.

Video: Big Bang• http://www.youtube.com/watch?v=mx8itzrdV7I• http://

www.ryancshaw.com/Files/micro/Animations/BacterialGrowth/PLAY_bacterial_growth.html

• Cell phones and bacteria• http://www.teachertube.com/viewVideo.php?

title=Cell_Phone_Bacteria&video_id=15882