Bacteria

Prokaryote – single celled with no nucleus Eubacteria – peptidoglycan (a carbohydrate) cell wall Archaebacteria – cell wall of lipids, no peptidoglycan in the cell wall

Identifying Prokaryotes Shape a. bacilli – rod shaped b. cocci – spherical shaped c. spirilla – corkscrew shape

Identifying Prokaryotes Cell Wall – use gram stain i. gram positive has peptidoglycan wall ii. gram negative has no peptidoglycan wall Movement – may or may not move >flagella >lash, snake, or spiral forward >glide on slime like secreted layer

Metabolic Diversity Heterotrophs: chemotrophs & photoheterotrophs Autotrophs >photoautotrophs – ex. Cyanobacteria hiddenecologies/HE/wp-content/uploads/ 2006

Metabolic Diversity >chemoautotrophs – energy from chemical reactions is used to make food (from ammonia, hydrogen sulfide (H 2 S), nitrites, sulfur, or iron)

Growth & Reproduction Binary fission

Growth & Reproduction Conjugation

Growth & Reproduction Spore Formation: structures of DNA & some cytoplasm (formed when conditions were unfavorable for growth) remain dormant for months or years until the right conditions exist daylily_rust_spores400x.jpeg

Importance of Bacteria Decomposers – recycle nutrients & maintain equilibrium Nitrogen fixers – change nitrogen gas into useable compound plants can use nitrogencycle.jpg

Importance of Bacteria Human use – make food & beverages, clean up oil spills, remove waste products from ground, synthesize drugs & chemicals, make vitamins our bodies need (E.coli in large intestine)

Viruses Virus: particles of nucleic acid, protein, & sometimes lipids (typically DNA or RNA core with a protein coat) >only reproduce by infecting living cells >use living cells to make more viruses Image by Karsten Schneider/Science Photo Library

Viruses Capsid: protein coat of a virus >capsids bind to cell host & “trick” the cellto let the virus inside the healthy cell Bacteriophages: viruses that only infect bacteria

Viral Infection Lytic – virus enters a cell, makes copies of itself, & causes the cell to burst Lysogenic - virus combines its DNA with the host cell and the viral DNA replicates with the host’s DNA

Viral Infection

Retroviruses Viruses that contain RNA Named retro because they copy genetic information from RNA to DNA (usually genetic information is copied from DNA to RNA

Retroviruses

HIV VIRUS

The “take-home” message STAY HEALTHY WASH YOUR HANDS, ETC.