Daily Warm-up March 6th What are the two reproductive cycles of viruses? HW: -Read 20.2, study for quiz tomorrow, test corrections Turn in: -Nothing

Prokaryotes

Prokaryotes vs. Eukaryotes…. No nucleus or other membrane-bound organelles Small Unicellular Eukaryotes Larger Nucleus and other membrane-bound organelles

Two Domains of Bacteria 1. Archaea Extremists High heat or high salt locations

2. Eubacteria Heterotrophs – get food from other organisms Autotrophs – Make their own food - photosynthesis Chemosynthetic Autotrophs – Convert chemicals from atmosphere and soil into food Eubacteria and Archaea are very different. Differences in cell wall composition, different RNA

Bacterial Structure? Capsule – sticky layer outside the cell wall (not all have this) Cell wall – supports and protects Plasma membrane – regulates what enters and leaves the bacterium Chromosome – one central loop of DNA (NOT a nucleus) Plasmids – small circular DNA segments Pili

Shapes: Bacillus Coccus Spirillium (Rod-shaped) (spherical) (spiral)

GROUPINGS DIPLO (TWO) STREP (CHAIN) STAPH (CLUSTER)

Movement Not all bacteria move but if they do they usually use Flagella Slime

Gram Stain Gram + Bacteria: turn purple (killed by antibiotic penicillin-attacks the cell wall) –Ex. Strep throat Gram – Bacteria: turn pink (killed by antibiotic tetracycline-doesn’t attack the cell wall) - Ex. E. Coli Antibiotics are drugs used to fight bacterial disease

Continuous loop of DNA Plasmids 1 µm Fig. 27-8 Figure 27.8 A prokaryotic chromosome and plasmids The typical prokaryotic genome is a ring of DNA that is not surrounded by a membrane and that is located in a nucleoid region 1 µm

Importance of Bacteria They change “FIX” NITROGEN from the air so organisms can use it Recycle nutrients (oxygen) Food: swiss cheese, pickles, yogurt, vinegar, sauerkraut E. Coli live in our intestines and help digest food Some antibiotics are made by bacteria

Bacteria can cause disease Strep throat Tuberculosis Tetanus Lyme Disease Dental cavities Diphtheria – from contaminated water The Bubonic Plague – transmitted from fleas STDs such as chlamydia, gonorrhea, syphilis Food Poisoning (E.Coli)

Reproduction Binary fission- one cell into two identical cells Conjugation- exchange of genetic material

What are the two types of prokaryotes? What are some ways that bacteria affect our lives? What shape is a bacterium if it is a coccus? Gram staining is important because?