Bacteria and Viruses

How much do you know about where bacteria is??? 1. What is the best way to eliminate bad breath? a. Mouth Wash b. Drink water c. eat mints 2. Is antibacterial soap significantly better than plain soap? a. yes. b. No 3. Do hospitals keep you safe from germs? A. yes. b. no 4. You have a greater Chance of getting sick when riding on an airplane. a. true b. false 5. The kitchen is the cleanest room in the house? A. True b. false 6. It is safe to share your makeup? A. true b. false 7. Toilet seats are the dirtiest thing in the bathroom. A. true b. False 8. Dogs have cleaner mouths than humans. A. true b. false

Helpful or Harmful?

What are the common Characteristics of Bacteria?

How does a bacteria cell compare with plant and animal cells How does a bacteria cell compare with plant and animal cells? What parts do bacterial cells have?

Bacterial Survival - Endospores Bacteria makes a thick internal wall which encloses its DNA and part of its cytoplasm *Stays dormant until conditions improve for bacteria to continue growing*

Bacterial Reproduction - Asexual Also known as BINARY FISSION Occurs when bacteria cell doubles its size, replicates its DNA and divides in half  2 daughter cells produced!

Bacteria Reproduction - Sexual Also known as CONJUGATION Occurs when bacteria transfers genetic material through cell to cell contact.

What characteristics do we use to identify bacteria? 1. Shape 2. Cell wall composition Nutrition and Respiration – some need O2, some don’t! 4. Movement – slide vs. flagella

Bacterial Shapes SPHERICAL ROD-LIKE SPIRAL (cocci) (bacilli) (spirilla)

Gram Positive and Gram Negative *Cell wall composition*

Disease Causing Bacteria Until the 19th Century, the Humans did not know about Germs Koch’s Postulates on Microbes causing Diseases

Robert Koch’s 4 postulates For determining whether a specific organism can cause disease: 1.) Isolate microorganism suspected of causing disease 2.) Grow microorganism in a pure lab culture 3.) Inject a healthy animal with the cultured microorganism. Observe to see if animal contracts the disease. 4.) If the animal becomes ill, re-isolate the microorganism that caused the illness. Compare this microorganism with the original.

How are Germs Spread? Direct – Goes Directly from one organism to the next. Indirect Air Vector – Water, object, food, etc.

Gram Positive Bacteria Bacillus - anthrax Streptococcus – strep throat, pneumonia Staphylococcus – skin infections, TSS, Respiratory infections Clostridium – tetanus, botulism

Gram Negative Bacteria Clamydias - Chlamidia Spirochetes – Lyme Disease, Syphilis

Bacillus Anthracis Anthrax 1 gram of the toxin can kill an entire city of people

Tuberculosis

Clostridium Clostridium Botulinum – Botulism Clostridium tetani – Tetanus

Escherichia coli

Salmonella

Staphylococcus aureus Food Poisoning Respiratory infections Toxic shock syndrome Skin infections

Spirochetes Lyme Disease Syphilis

Stomach Ulcers Heliobacter pylori

Antibiotics and Resistance Antibiotic Resistance – How Big of Problem is it becoming? Are antibiotics really what has helped improve the average length of the Human Life?

How is bacteria helpful? Even though some bacteria is harmful, it can be helpful in the following ways: 1.) Sewage treatment - the breakdown of animal and plate waste 2.) Food production – buttermilk, sour cream, yogurt, cottage cheese, sauerkraut, pickles 3.) Industrial chemical production 4.) Nitrogen fixers (make nitrogen for plants to make amino acids) 5.) assists us in cleaning up environmental disasters – such as oil spills 6.) Supply vitamins that we need – in our intestines!

VIRUSES Noncellular particle made up of genetic material and protein that can invade living cells Can only be seen with electron microscope Has a core of nucleic acid (DNA/RNA) surrounded by a protein coat Can reproduce, but must invade (infect) a living host cell…cannot function without one Cause diseases such as AIDS, hepatitis B, genital warts, some types of cancer, colds

VIRUSES LIFE CYCLE: 1.) Infection – injects its DNA or RNA into host cell 2.) Growth – host cell replicates viral DNA, takes over host cell 3.) Replication – uses materials from host cell to produce more of the virus, then infected cell bursts and releases more viruses to infect other cells