1. Bacteria

2. KEY CONCEPT Bacteria and archaea are both single-celled prokaryotes.

3. What are Bacteria?
Prokaryotes - Cells that do not have their DNA contained in a nucleus (All Bacteria!)
There are two Kingdoms of unicellular prokaryotic organisms:
Archaebacteria
Eubacteria (“eu” meaning true bacteria).

4. Archaebacteria
In their own domain Archaea because they are so different molecularly from true bacteria.
They are prokaryotic, unicellular and live in extreme environments (no oxygen, high salt, high temperatures, etc.)
Their cells walls do not contain peptidoglycan.

5. Eubacteria In the Domain Bacteria.
They are prokaryotic, unicellular, and live all over the world, around, in and on organisms (yes, all inside of you!)
Their cell walls are made of peptidoglycan.

6. Bacteria and archaea have similar structures. plasmid flagellum pili
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.

7. Parts of Bacteria
Plasma (cell) membrane- selectively permeable for material exchange
Cell Wall- made of peptidoglycan in Eubacteria
DNA- contained in a “nucleoid region”
Pili- small protein extensions used to anchor themselves OR sex pili aid in exchanging DNA
Flagella- whip-like tail for movement
Ribosomes- translate genetic material into proteins

9. 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

10. Bacteria commonly come in three forms. rod-shaped, called bacilli
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
Spirochaeta: spiral
Enterococci: spherical
Archaea have many shapes.

11. Coccus
Spirillum
Bacillus

12. Bacteria and archaea have molecular differences.
The amount of peptidoglycan within the cell wall can differ between bacteria
GRAM NEGATIVE
GRAM POSITIVE
Archaea have different lipids entirely

13. Classification- Gram staining
Bacteria are identified by how THICK their cell wall is. Scientists use a method called Gram staining to identify certain kinds of bacteria.
Gram + : bacteria stains purple, meaning they have a thick cell wall of peptidoglycan
Gram - : bacteria stains light pink (or red), meaning they have a thin wall of peptidoglycan

14. Gram staining identifies bacteria. stains polymer peptidoglycan
gram-positive stains purple, more peptidoglycan
gram-negative stains pink, less peptidoglycan
Gram-negative bacteria have a thin layer of peptidoglycan and stain red.
Gram-positive bacteria have a thicker peptidoglycan layer and stain purple.

15. Metabolism
Bacteria can be classified by how they obtain energy and use it. They can be…
heterotrophs (must consume food)
autotrophs (can make their own food).
Chemoautotroph – make their own food starting with inorganic molecules
Photoautotroph – make their own food using light

16. Reproduction
Most bacteria reproduce very quickly by a process called binary fission, some only taking 20 minutes to divide.
They reproduce asexually, meaning they simply divide without combining genetic material.
Small parts of DNA can be exchanged through sex pili. They act like little tunnels through which DNA can be exchanged.

18. Bacteria have various strategies for survival.
Prokaryotes exchange genes during conjugation.
conjugation bridge
TEM; magnification 6000x
Bacteria may survive by forming endospores.

19. KEY CONCEPT Prokaryotes perform important functions for organisms and ecosystems.

20. Importance of Bacteria
We think of bacteria as being all bad, but actually we need them greatly!
Bacteria are vital to maintaining the living world.

21. Human uses
We have bacteria living on all surfaces of our bodies and ones such as E. coli are essential for our digestion. We provide them with a warm environment, and they provide us with essential vitamins that we cannot produce on our own. This too is a mutualistic symbiotic relationship.

22. Bacteria help ferment many foods.
yogurt, cheese
pickles, sauerkraut
soy sauce, vinegar

23. Prokaryotes play important roles in ecosystems.
Prokaryotes have many functions in ecosystems.
photosynthesize
recycle carbon, nitrogen, hydrogen, sulfur
fix nitrogen

24. Importance
2. Decomposers: when all organisms die, their organic matter must be returned to the soil for other organisms. Decomposers complete the carbon cycle.

25. Pathogens- harmful bacteria
Any disease causing agent is called a pathogen- it could be bacterial or viral
Harmful Bacteria-cause disease in one of two ways:
Breaking down our body’s cells as food
Releasing toxins that travel through the body and damage our cells

26. Some bacteria cause disease.
Bacteria cause disease by invading tissues or making toxins.
A toxin is a poison released by an organism.

27. Normally harmless bacteria can become destructive.
may colonize new tissues

28. Normally harmless bacteria can become destructive.
immune system may be lowered

29. Lyme Disease Cause: Borrelia burgdorferi
Symptoms: fever, fatigue, headaches, muscle aches, joint aches, Bulls-eye shaped rash
Transmission: tick bite
Treatment: antibiotics

30. Tetanus (Lock jaw)
Cause: Clostridium tetani Toxins released by bacteria interfere with nervous system
Symptoms: Severe muscle spasms and possibly death
Transmission: Commonly contracted from deep puncture wound or self-piercing with contaminated materials

31. Tetanus (Lock jaw) Treatment: Clean wound
Mild: given antibodies against it, with antibiotics, and a vaccine
Severe: same as above, muscle relaxers or even paralytic drugs to stop the spasming

32. Tuberculosis (TB) Affects nearly 1/3 of the world’s population
Cause: Mycobacterium tuberculosis
Symptoms: Fatigue, weight loss, fever, chronic cough Tubercles form in lungs (dormant form)
Transmission: Spread through cough
Treatment: long term antibiotic treatment (6-12 months)

33. Gonorrhea Cause: Neisseria gonorrhoeae Male symptoms: Female symptoms:
Thick, foul-smelling discharge from penis
Painful urination
Testiculur and abdominal pain
Female symptoms:
Pus-like vaginal discharge
Pain urinating
Bleeding after intercourse
Transmission: oral, anal, or vaginal sex
Treatment: with antibiotics

34. Chlamydia One of the most common STIs on college campuses
Transmission: oral, anal, or vaginal sex; mother to child during childbirth through vaginal canal
Treatment: with antibiotics
One of the most common STIs on college campuses
Cause: Chlamydia trachomatis
Symptoms: Burning during urination, discharge from the penis or vagina, pain and itching

35. Strep Throat
Cause: Streptococcus pyogenes, certain strains cause scarlet fever and Toxic Shock Syndrome
Symptoms: fever, sore throat, swollen glands
Transmission: respiratory droplets (coughing sneezing)
Treatment: antibiotics can cause it to go away faster
Purple  gram +

36. Tooth Decay Cause: Streptococcus mutans, bacteria doubles in 24 hours
Symptoms: Destruction of tooth enamel
Transmission: resident in mouth
Treatment: brush and floss daily

37. Bacterial meningitis Cause: Neisseria meningitis
Symptoms: high fever, headache, stiff neck, nausea, fatigue
Transmission: most common in college dorms
Treatment: antibiotics, early detection is essential

38. Anthrax Used in Bioterrorism
Cause: Bacillus anthracis, a spore-forming bacteria
Transmission/Symptoms of varying types:
Spread by eating undercooked meat (vomiting and diarrhea, possible death)
breathing in spores (usually fatal)
skin contact (ulcers, rashes, not fatal)
Treatment: oral and IV antibiotics

39. Botulism- food poisoning
Cause: Clostridium botulinum
Symptoms: blurred vision, slurred speech, difficulty swallowing, muscle weakness, paralysis
Transmission: From a wound, contaminated food
Treatment: antibiotics
FACTOID: Botox is a toxin secreted by Clostridium botulinum

40. Staphylococcus aureus
Pets can carry bacteria as well!
Staphylococcus aureus
Gram +
Cause: Staphylococcus aureus
Symptoms: nausea, cramping, retching; some individuals may not show symptoms
Transmission: eating contaminated food, contaminated air, individuals and surfaces
PETS!

41. Preventing Disease
1. Good hygiene- wash hands thoroughly with soap and water (you don’t need antibacterial!!!), brush teeth and floss (bacteria in your mouth DOUBLES in 24 hours); take care with who your drink after, check ups at the doctor

42. Preventing Disease
2. Vaccine- a weakened or dead form of the pathogen is given to a patient whose body will form an immune response to it. Once that immune response happens, your body remembers it forever and if the real pathogen gets in your body, your immune system will react quickly and kill it immediately.

43. Preventing Disease
3. Antibiotics- if infection does occur, antibiotics can be given. They prevent growth and division of bacteria so that our immune systems can conquer the illness more easily. Unfortunately, bacteria evolve in response to this pressure and we have many antibiotic resistant diseases now.