Bacteria & Viruses Unit 6 – Lecture 1

Note: Read and LISTEN!! I mentioned this at the beginning of the year and semester , but as the year progresses, you’ll have less and less notes given on the screen… in this unit, you’ll have both information on the screen itself, AND info that you’ll need to listen for [not everything will be on the board] so Read and LISTEN!!

Recall Classification Organisms are classified by: cell type body type how they attain nutrition genetic composition

Domains There are three domains of Life: Bacteria Archaea Eukarya

Domain: Bacteria Kingdom Eubacteria prokaryotic unicellular

Domain: Bacteria Kingdom Eubacteria asexual reproduction sometimes with conjugation using pili [sing = pilus]

Domain: Bacteria Kingdom Eubacteria strong cell wall can be autotroph or heterotroph saphrophyte parasite chemoautotroph photoautotroph

Domain: Bacteria Kingdom Eubacteria found almost everywhere except for extreme environments some have locomotion flagella cilia

Domain: Bacteria Kingdom Eubacteria three basic body shapes: bacillus coccus spirillum strep = chains staph = clusters

Discuss Summarize the characteristics of Eubacteria and check over your notes with a partner to make sure you got everything.

Domain: Archaea Kingdom Archaebacteria prokaryotic unicellular asexual reproduction sometimes with conjugation

Domain: Archaea Kingdom Archaebacteria strong cell wall with unique composition autotrophic photoautotroph chemoautotroph

Domain: Archaea Kingdom Archaebacteria closer genetically to eukaryotes than eubacteria live in extreme environments high heat, high salt

Discuss Summarize the characteristics of Archaebacteria and check over your notes with a partner to make sure you got everything.

Domain: Eukarya Kingdoms Protista, Fungi, Animalia, Plantae very diverse but all are eukaryotic unicellular or multicellular highly organized sexual or asexual reproduction

Recall – Characteristics of Life It is debatable if viruses are truly alive or not. Discuss with a partner whether or not you think a virus fulfills the characteristics which all living things must have. organized (into cells) reproduces can pass traits to offspring grows/develops needs energy maintains homeostasis responds to stimuli ?

Viruses Multiple forms: helix icosahedral bacteriophage and more

Viruses Nucleic Acid Bacteriophage anatomy [aka T-4 bacteriophage or just “phage”] head = capsid sheath aka tail Nucleic Acid

Viruses Reproduction must occur in a host cell two cycles: lytic cycle lysogenic cycle

Viruses Lytic Cycle attachment infection incorporation of nucleic acid replication: viral DNA uses host to replicate DNA and make more viruses destruction of cell

Viruses Lysogenic Cycle attachment infection incorporation of nucleic acid DNA is dormant & replicates with cell info during cell cycle

Viruses Prion – “evil misshapen protein” / viral protein responsible for mad cow disease which destroys brain tissue recent discoveries, however, show that “normal” prions may have an important role in keeping nerve cells healthy

Viruses Uses for viruses vaccines gene therapy Cystic Fibrosis

Recall – Characteristics of Life So…are viruses alive? Why or Why Not? Which characteristics does it share with living things? organized (into cells) reproduces can pass traits to offspring grows/develops needs energy maintains homeostasis responds to stimuli ?

Homework Complete the worksheet on the backside of your lecture notes Draw, Label & Color Bacteria & Viruses