1. Prokaryotes
Bacteria were first discovered in the late 1600’s by Anton van Leeuwenhoek, using the microscope he invented.
bacteria found in the dental plaque of two old men who never cleaned their teeth.

2. Prokaryote Structure
Prokaryotes are simple cells. NO NUCLEUS- The DNA is loose in the cytoplasm in the form of a NUCLEOID
- The RIBOSOMES are found in the cytoplasm.- NO ORGANELLES
Has a CELL MEMBRANE and CELL WALL (peptidoglycan not cellulose)
Some have an outer CAPSULE which is sometimes called a SLIME LAYER or PILI which are tiny stickers
Bacteria move using FLAGELLA: may have one or many

3. Relationship to Oxygen
For more than half of Earth’s history, oxygen wasn’t present in the atmosphere. Many bacteria evolved under anaerobic conditions.
Classification:
OBLIGATE AEROBES(need oxygen to survive)
OBLIGATE ANAEROBES (killed by oxygen)
AEROTOLERANT(don’t use oxygen, but survive it).
FACULTATIVE AEROBES(use oxygen when it is present, but live anaerobically when oxygen is absent).

4. 2 Bacteria Kingdoms
Kingdom Archaebacteria - are ancient bacteria that live in extreme environments
First appeared approximately 3.7 BYA
Kingdom Eubacteria - are generally referred to as bacteria or germs, and are considered more recent. Most types of bacteria belong in this kingdom.

5. The Archaebacteria:
do not have peptidoglycan in their cell walls
have ribosomes similar to eukaryotes
have unique lipids in their plasma (cell) membranes

6. The Archaebacteria also:
have some genes that resemble eukaryotic genes
usually are not pathogenic (they don’t usually make us sick!)
live in extreme environments:
high concentrations of salt
extremes of pH and temperature

7. 3 Archaebacterial Groups
Methanogens- turn H2 and CO2 into methane (CH4)
Halophiles- organisms that live in environments with extremely high salt concentrations
Thermoacidophiles = live in extremely hot, acid environments

8. Methanogens
anaerobic bacteria that get energy by turning H2 and CO2 into methane (CH4)
live in mud, swamps, and the guts of cows, humans, termites and other animals

9. Halophiles
are organisms that live in environments with extremely high salt concentrations
some extreme halophiles can live in solutions of 35 % salt. (seawater is only 3% salt!)
halophile means “salt loving”
most halophiles are aerobic and heterotrophic; others are anaerobic and photosynthetic, containing the pigment bacteriorhodopsin

10. Halophile Environments solar salterns Owens Lake, Great Salt Lake,
coastal splash zones,
Dead Sea

11. Thermoacidophiles the first Extremophile was found about 30 years ago
Like temperature and pH extremes
Hot = up to 110ºC
Cold = down to 1ºC
Acid = as low as pH 2
Alkali = as high as pH 9
they are chemoautotrophs, using H2S
the first Extremophile was found about 30 years ago

12. Thermophile Environments Hydrothermal Vents in the ocean, and
Obsidian Pool in Yellowstone National Park

13. EUBACTERIA---
Germs
PATHOGENS- an organisms that makes another organism sick by living inside
Examples- bacteria, viruses, fungi, parasites

14. CLASSIFIED BY METABOLISM
AUTOTROPHIC PHOTOAUTOTROPHIC CHEMOAUTOTROPHIC HETEROTROPHIC AEROBIC ANAEROBIC

16. Bacteria are Named by Shape
Cocci (ball-shaped)
Streptococcus mutans
Bacillus (rod-shaped)
Clostridium botulinum
Spirilli (spiral-shaped)
Treponema palladium

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18. Bacteria are Named by Arrangement
Paired: diplo
Grape-like clusters: staphylo
Chains: strepto

19. Examples Streptococcus: chains of spheres
Staphylospirillum: Grapelike clusters of spirals
Streptobacillus: Chains of rods

21. CLASSIFIED BASED ON THEIR CELL WALL
The Gram stain, which divides most clinically significant bacteria into two main groups, is the first step in bacterial identification. BACTERIA WITH THICK CELL WALLS – are called GRAM + and will stain purple BACTERIA WITH THIN CELL WALLS- are called GRAM – and will stain pink

22. The Gram stain has four steps:
1. crystal violet, the primary stain: followed by
2. iodine, which acts as a mordant by forming a crystal violet-iodine complex, then
3. alcohol, which decolorizes, followed by
4. safranin, the counterstain.

23. In Gram-positive bacteria, the purple crystal violet stain is
trapped by the layer of peptidoglycan which forms the outer
layer of the cell. In Gram-negative bacteria, the outer
membrane of lipopolysaccharides prevents the stain from
reaching the peptidoglycan layer. The outer membrane is then
permeabilized by acetone treatment, and the pink safranin
counterstain is trapped by the peptidoglycan layer.

24. Is this gram stain positive or negative? Identify the bacteria.

25. Is this gram stain positive or negative? Identify the bacteria.

26. Fission is a type of asexual reproduction
Reproduction of Bacteria
Binary Fission- the process of one organism dividing into two organisms
Fission is a type of asexual reproduction
Asexual reproduction- reproduction of a living thing from only one parent
How?...
The one main (circular) chromosome makes a copy of itself
Then it divides into two
www-raider.stjohns.k12.fl.us/.../ sv16.html

27. BINARY FISSION Bacteria dividing Completed Reproduction of Bacteria
Bacteria dividing
Completed

28. Some can reproduce every 20 minutes
Reproduction of Bacteria
The time of reproduction depends on how desirable the conditions are. (example- leaving milk out vs keeping them in the refridgerator)
Some can reproduce every 20 minutes
(one bacteria could be an ancestor to millions in less than a day)
“EXPONTENTIAL GROWTH”

29. Binary Fission Bacterial Cell & Nucleiod DNA Ring Step 1
DNA replicates
Binary Fission
Step 2
DNA (chromosomes) move to opposite ends and attach to cell membrane
Step 3-Cell grows in the middle
Step 4 – Cell wall forms between the two daughter cells

30. How do bacteria survive in inclimate environments?
CAPSULES-(Gram -) prevent bacteria from drying out
GLYCOCALYX- capsule with a sticky substance that allows the bacteria to stick to a specific environment
ENDOSPORES- dormant structure that surrounds the DNA in Gram + bacteria

31. ENDOSPORE

32. How do Bacteria become drug resistant? (DNA)
MUTATIONS-
PLASMIDS- tiny rings of DNA that can be transferred from one bacteria to another
TRANSFORMATION-absorbing DNA from the environment (example- other bacteria that have died)
TRANSDUCTION- Virus carries DNA from one bacteria to the next
CONJUGATION- passing of DNA from one bacteria to the next

33. TRANSFORMATION

34. CONJUGATION
STEP 1- Bacteria replicates a PLASMID STEP 2- Bacteria creates a CONJUGATION BRIDGE from one bacteria to the next STEP 3- PLASMID crosses the CONJUGATION BRIDGE STEP 4- PLASMID may or may not become part of the chromosome of the new bacteria

35. TRANSDUCTION

36. CONJUGATION

37. CONJUGATION

38. BENEFITS OF BACTERIA
1. DECOMPOSERS—Saprophytes- breakdown dead organisms and place nutrients back into the soil (important in the carbon cycle, nitrogen cycle)
2. NITROGEN FIXATION- extremely important in the nitrogen cycle- bacteria called RHIZOBIUM- are found in the roots of LEGUMES (bean plants). These rhizobium can turn unusable nitrogen into a type of nitrogen that plants can use to make proteins. (examples- crop rotation)

39. BENEFITS OF BACTERIA
3. Make foods like- PICKLES, CHEESE, BUTTER, YOGURT (Lactobacilli and bifidobacterium), SAUERKRAUT , SAUSAGES, COCOA and COFFEE BEANS—SOUR DOUGH BREAD
Live in our digestive systems (ENTERIC BACTERIA)- help us breakdown hard to digest food and produces VITAMIN K (example- E. coli)
Live on our skin– Staphylococcus epidermis protects us from other bacterial invaders

40. BIOTECHNOLOGY WITH BACTERIA
6. USING BACTERIA to clean up OIL SPILLS- break it down and give off carbon dioxide and water
USING BACTERIA to de-thatch your YARD and in PEST CONTROL
USING BACTERIA to produce certain PROTEINS and INSULIN used in medicine

41. PROBLEMS WITH BACTERIA
EUTROPHICATION
“population bloom” of bacteria (fungi or plants) that use up all the nutrients in a lake, pond- most commonly OXYGEN that will kill off all animals in the area

42. PROBLEMS WITH BACTERIA
PATHOGENS- give off toxins that cause diseases EXOTOXINS- toxins released by living bacteria-usually made by Gram + bacteria- (Example- tetanus) ENDOTOXINS- toxins that are released when the cell dies- from the capsule of Gram – bacteria (Example- E. coli)

43. ANTIBIOTICS
Defined as drugs that “combat” bacteria that interfere with their cellular functions ANTI= not or against BIO= living

44. Types of ANTIBIOTICS (See list on pg 479)
PENICILLIN- interferes with the bacteria’s ability to make a cell wall (Gram +)
TETRACYCLINE- interferes with the bacteria’s ability to make proteins-- BROAD SPECTRUM ANTIBIOTIC
METHICILLIN- strongest antibiotic we have
VANCOMYCIN- currently the antibiotic of last resort