VIRUSES (What the heck are they?)

2 The Common Cold Virus

3 Oh Goodness, My E. coli has a Virus! Viruses and Bacteria It's easy to mix these up since compared to us, both are VERY SMALL. Great link for size comparison! Source:

4 The basics  Viruses are:  non-living  much smaller than the smallest cell  pieces of genetic coding (DNA or RNA) “gift-wrapped” in a protein coat

5 Diversity of Capsids

6 Diseases caused by viruses include: Common cold Flu Polio Rabies Herpes (chickenpox,cold sores, genital) Warts Measles, Mumps Ebola AIDS Viruses cannot be killed with antibiotics because they are not alive!

7 Antibodies attacking AIDS Virus

8 Diversity of Life Introduction to Prokaryotes

9 Figure 13.27a

10 Figure 13.27b

11 Prokaryote Diversity

12 Two types of Prokaryotic organisms: Eubacteria (bacteria) and Archaea Visual Summary 15.3 Prokaryotes Domain Bacteria Domain Archaea (e.g., extremophiles)

13 Archaea – Thermophiles in a Nevada geyser.

14 Archaea in a hot spring.

15 Archaea – Halophiles in seawater evaporating ponds near San Francisco Bay. Salinity increases from 3% to 20% during the production of salt.

16 Archaea (a.k.a. “Archaeabacteria)   Prokaryotic (like eubacteria)   Biochemically resemble eukaryotic cells   Believed to be the ancestors of eukaryotic cells   Today: only live in harsh environments

17 (Bacteria Review) What do you already know about bacteria??

18 Bacteria on the tip of a pin.

19 Major Episodes in the History of Life Visual Summary 15.1 Millions of years ago ,000 1,700 2,500 3,500 4,500 Major Episode Plants and fungi colonize land All major animal phyla established First multicellular organisms Oldest eukaryotic fossils Accumulation of atmospheric 0 2 Oldest prokaryotic fossils Origin of Earth

20 ALL CELLS have Plasma membrane DNA ribosomes

Generalized structure of bacteria cell

22 Figure4.5x2

23 Bacterial shapes: cocci, rods, spirals

24 Cyanobacteria or “blue-green algae”

25 Bacterial colonies growing in culture.

26 Detriments to Humans Bad breath, tooth decay Food poisoning Some are pathogenic pathogenic –

27 Some Diseases caused by bacteria Strep throat Cholera Tubercolusis “the plague” Anthrax Toxic shock syndrome Syphilis, Gonorrhea,

28 How cure bacterial infections? (Antibiotics)

29 Discussion Question: Should we drop “bacteria bomb?” Are there benefits to bacteria that outweigh their detriments to humans????

30 Benefits of Bacteria Decomposers!  chemical cycling Cyanobacteria were original producers of oxygen atmosphere  ozone Origins of mitochondria & chloroplasts Aid humans in digestion (E. coli) Allow cows to digest cellulose (grass)  milk, ice cream, hamburgers! Lactic acid fermentation (yogurt, buttermilk, sauerkraut) bioremediation Nitrogen “fixers” (to be explained in Unit IV!)