Bio 104 Prokaryotes Bacteria and Archaea

• -are unicellular organisms without a nucleus or organelles
• -Includes bacteria and archaea as domains.
• -Genetically diverse
• -Thrive almost anywhere on earth.
• -Spherical, Rod-shaped, and spiral
• -lack membrane bound organelles 
• -less DNA than eukaryotic in a circular chromosome
• -might have a smaller ring of DNA known as a plasmid for exchange.

On the cell surface there is a wall, pili for attachment and/or sex, and a flagellum.

Found in bacterial cell walls. A network of sugar polymers and polypeptides.

Polysaccharides (sugars), and proteins

NOT peptidoglycan

Cellulose and / or chitin

Measures the amount of peptidoglycan in cell walls. Gram-negative have less and are more antibiotic resistant and toxic.

Fimbriae which are used for attachment and sex pili

Ability to move away or toward certain stimuli.

• Binary fission and divides every 1-3 hours.
• Low mutation rate but divides rapidly
• Might release endospores which float around and have a high survival rate.
• Budding.

Rapid reproduction leads to an eventual mutation.

Genetic recombination (3 types)

When a cell divides asexually producing two identical daughter offspring.

• -Transformation:
• A prokaryotic cell can take up and incorporate foreign DNA from the surrounding
• environment

• -Transduction
• is the movement of genes between bacteria by bacteriophages (viruses that
• infect bacteria)

• -Conjugation
• is the process where genetic material is transferred between bacterial cells
• (might be important in Archaea)

Autotrophs, phototrophs, heterotrophs, and chemotrophs

Nitrogen-fixing cells that work with cyanobacteria to exchange metabolic products.

Metabolic cooperation to coat a surface.

Living in extreme areas.

Live in highly saline emvironments

Live in very hot environments