1. Bacteria and Archaea

2. Cell Structure Prokaryote: no nucleus
Chromosome & plasmids float freely in cytoplasm
Ribosomes: create proteins
Flagella: used in movement
Pili: act as anchors
Capsule: outer coating
Endospore: “cocoon” to
protect DNA in harsh times
flagellum
pili
plasmid
cell wall
chromosome
plasma membrance
This diagram shows the typical structure of a prokaryote. Archaea and bacteria look very similar, although they have important molecular differences.

3. Prokaryotes are widespread on Earth.
Prokaryotes can be grouped by their need for oxygen.
obligate anaerobes are poisoned by oxygen
obligate aerobes need oxygen
facultative aerobes can live with or without oxygen
The bacteria that causes TB lives in your lungs…which type is it?

4. Bacteria and archaea are structurally similar but have different molecular characteristics.
Bacteria commonly come in three forms.
rod-shaped, called bacilli
spiral, called spirilla or spirochetes
spherical, called cocci
Lactobacilli: rod-shaped
Enterococci: spherical
Spirochaeta: spiral
Spirochaeta:spiral
Enterococci: spherical
Archaea have many shapes.

5. Bacteria (aka Eubacteria)
Common to most environments on Earth
Identified by Gram Stain test
Gram negative: stains pink (harder to treat because of thick capsule)
Gram positive: stains purple (easier to treat)
Treatments differ depending upon results
GRAM NEGATIVE
GRAM POSITIVE

6. Gram Stains Which is harder to treat?
Gram-negative bacteria have a thin layer of peptidoglycan and stain red.
Gram-positive bacteria have a thicker peptidoglycan layer and stain purple.
Which is harder to treat?
Name one way to treat bacterial infections.

7. Bacteria have various strategies for survival.
Reproduce asexually- through binary fission (less diversity).
Prokaryotes exchange genes during conjugation (more diversity).
Bacteria may survive by forming endospores.
conjugation bridge
TEM; magnification 6000x

8. Not all bacteria are harmful, most are helpful…
Bacteria helped create the ozone.
Ex: cyanobacteria-autotrophic bacteria
Create oxygen for life on earth
Bacteria return nutrients to the soil in nature
Ex: saprophytes
Bacteria used in medicine
Bacteria used in food
To make cheese, bread, wine, yogurt, soy sauce
But some are bad…

9. Brush, Floss, & Rinse Your Teeth! GINGIVITIS HEALTHY
MODERATE PERIODONTITIS
ADVANCED PERIODONTITIS

10. Archaea are like an evolved
extreme bacteria.
Let’s look at those…

11. Archaea Live in extreme environments 1) Methanogens: Anaerobic
Produce methane gas as a waste product
Habitat: Swamps, sewage, digestive tract

12. Archaea 2) Thermophiles Heat and acid loving prokaryotes
Habitat: Deep sea vents, volcanoes, hot springs (230°F)

13. Archaea 3) Halophiles Thrive in areas of high salt concentration
Salt normally dehydrates organisms
Use salt to make energy

14. Name this bacteria shape!
Cocci

15. Name this bacteria shape!
Bacillus

16. Name these cell parts!
Pili

17. Name the process shown in this animation.
Binary Fission