Unit 11 - Microbiology

I. Life functions1. Transport - how materials move throughout an organism2. Excretion – how an organism removes waste3. Respiration – how an organism exchanges gas (carbon dioxide and oxygen)4. Nutrition – how an organism gets nutrients from food5. Reproduction – how an organism produces offspring

a. sexual reproduction – 2 parents with offspring expressing variationb. asexual reproduction – 1 parent with identical offspringc. hermaphrodite – produces both eggs and spermd. internal fertilization – egg and sperm meet inside the animal’s bodye. external fertilization – egg and sperm meet outside the animal’s body

II. MicrobiologyThe branch of biology that deals with microorganisms and their effects on other living organisms.

A. Viruses1. General information• Non-living particles w/DNA or RNA• Not made of cells• Do not carry out respiration or grow• Only reproduce inside of a living host

cell • Very small—1/1000th the size of a

bacteria• Examples: Influenza (flu), HIV, rabies,

chicken pox, common cold, ebola

Rabies Virus

Adenovirus

2. Viral structure:• Inner layer: Made of DNA or RNA

(nucleic acids)• Outer layer: Called capsid, a protein

layer for protection• *some viruses have an extra outer

envelope of protection – makes them harder to destroy

• Viral shape is specific, based on the type of cell it will invade

DRAW THIS

Example of viral structure

3. Steps of viral invasion1) Initiation: Virus attaches to host cell at a specific point on the plasma

mem, opens up & its RNA or DNA enters the cell2) Replication: Viral DNA/RNA takes over the metabolism of the cell –

forcing the cell to make more viruses3) Release: host cell bursts (dies) and releases replicated viruses• **Bacteriophage: special virus that invades a bacteria

4. Antibiotics don’t work on viruses (b/c they are considered nonliving). They only work on eukaryotic cells w/ a cell wall (make holes in c.w.)

B. Bacteria1. General Information • Members of Kingdoms Archaebacteria and

Eubacteria• Prokaryotic cells• Unicellular• May be autotrophic or heterotrophic• Shapes—part of their name

a. Bacilli: rod-shapedb. Spirilli: spiral-shaped c. Coccus: sphere-shaped

• ExamplesStreptococcus, pneumonia, Staphlococcus aureas, Bacillus thuringensis, Escherichia coli

2. Bacterial structure• Nucleoid: region where bacterial DNA is located

(not the same thing as a nucleus)• Cell Wall: protects bacterial cell, made of

cellulose and surrounds the plasma membrane• Capsule: for protection• Plasma membrane: maintains homeostasis of the

cell (allows substances to enter/leave the cell)• Pili: hair-like extensions of the plasma

membrane to help the bacteria stick to surfaces and exchange DNA during sexual reproduction (conjugation)

• Plasmid: circular DNA of the bacteria• Flagella: whip-like tail that enables bacteria to

move

DRAW THIS

3. Gram Staining • Lab technique used to distinguish different types of bacteria. 2 types1. Gram (+): thick cell wall, absorb lots of purple stain2. Gram (-): thin cell wall, absorb little of the purple stain

4. Antibiotics• Antibiotics will kill prokaryotic cells (bacteria) by breaking down their

cell wall and interfering with their metabolism and reproductive cycles

5. Bacterial reproduction:1. Binary fission (asexual): producing 2 identical bacteria

a.no genetic variation – identical to parent2. Conjugation (sexual): where 2 bacteria exchange DNA thru pilli and then they divide

a. causes genetic variation – how bacteria get differences and are able to adapt

6. Bacteria and oxygen: 1) Obligate aerobe:

a. Bacteria that require oxygen to live b. Example: tuberculosis (TB) => attacks the lungs

2) Obligate anaerobe:a. Bacteria that does not require oxygen (will die in presence of oxygen) b. Example: botulism => spoiled canned foods

3) Facultative aerobes:a. can live with or without oxygen

7. Why are bacteria bad?1) Disease: can cause diseases such as strep throat, infectious and contagious (can spread quickly)2) Food spoilage: can cause food to spoil and become poisonous

8. Why are bacteria good?1) Nitrogen fixation: Converts nitrogen from a gas in the air to a solid form that plants can use when growing

a. Example: soybean plant w/ bacteria in roots2) Decomposers: recycle nutrients

a. Examples: decompose dead organisms and break down chemicals from oil spills3) Make foods: Used to make cheeses, vinegar, yogurt4) Medicines: Used to make medicines like bacitracin, neosporin

Videos

• Bacteria dividing - http://www.youtube.com/watch?v=gEwzDydciWc • Cell phone -

http://www.youtube.com/watch?v=4lmwbBzClAc&feature=related • Virus invasion - http://www.npr.org/blogs/krulwich/2011/06/01/1140

75029/flu-attack-how-a-virus-invades-your-body

C. Protists1. General information• Kingdom Protista• Eukaryotes• Unicellular or multicellular• Autotrophic or heterotrophic• Have contractile vacuoles: vacuole that contracts to

maintain water levels; pumps out excess water so the cell does not burst and die• Most diverse kingdom• 3 groups

- Protozoan (animal-like)- Algae (plant-like)- Fungus-like

Protozoans (animal-like): 1. Amoeba – moves using

pseudopodia (false foot) – an extension of the plasma membrane – surrounds food in order to eat it

2. Flagellate – moves using flagella

3. Ciliate – moves using cilia, short hair-like extensions (ex. Paramecium)

4. Sporozoan – no self-propulsion – produce spores many of which are parasitic (ex. malaria parasite Plasmodium)

Amoeba Flagellate

Ciliate

Sporozoan

5. Diseases caused by protozoansA. Amoebic Dysentery –- caused by amoeba-spread by water and food- can be treatedB. Malaria – - mosquito-borne disease- caused by Plasmodium parasites in red blood cells- widespread in tropical and subtropical areas- antimalarial medications are available but mosquitoes are becoming resistant to some

• Malaria life cycle

Video

• Amoeba - http://www.youtube.com/watch?v=y-g5tGsZekU&feature=related • Flagellate - http://www.youtube.com/watch?v=9duvzqvVflw • Examples of ciliates (paramecium) and flagellates (paramecium) -

http://www.youtube.com/watch?v=QGAm6hMysTA • Plasmodium (causing malaria) -

http://www.youtube.com/watch?v=JwsoK8O0lXE • Amoeba travel to brain (from the water) -

http://www.cnn.com/2011/HEALTH/08/17/amoeba.kids.deaths/ -

Describe the following and try to identify them – A. B. C.

Algae • plant-like organisms that carry out

photosynthesisa. Euglena: use flagella to move, have eye-spots for detecting light sources

• can be heterotrophic if the organism cannot find enough light to carry out photosynthesis

b. Diatoms: have hard outer shells made of silicates (minerals)

• Example: phytoplankton

c. Dinoflagellates: have 2 flagella, usually these organisms produce poison (toxins) that cause fish kills

• Example: Red Tide

d. Kelp: multicellular algae• Example: Seaweed in sushi

Euglena

Diatoms

Kelp

Fungus-like protistsa. Examples: Slime molds, water molds, & downey mildewb. Damage to crops and food stores (Irish potato famine)Video - http://www.youtube.com/watch?v=GScyw3ammmk

D. FUNGUS1. General information• Kingdom Fungi• Unicellular or multicellular• Eukaryotic • Heterotrophic (decomposers)• Role: Decompose (breakdown) decaying

matter and recycle nutrients into the soil• Examples of fungus:

a. Unicellular yeast (what makes your bread dough rise)

b. Multicellular mushrooms, molds(like on month-old bread)• Fungus can grow anywhere: in air, water,

gardens, basement walls, between your toes

2. Structure of fungus• have cell walls made up of chitin – this is different than plant cell walls

or bacterial cell walls.

3. Negative aspects of Fungi:1) Spoil foods (mold)2) Diseases (ringworm, athlete’s

foot)3) Poison (mushroom)

4. Positive aspects of Fungi:4) Decomposers of wastes, dead

things5) Medicines (penicillin) and food

(blue cheese)

5. Diseases caused by fungus:A. Athlete’s foot - Scaly, flaky, itchy skin- Can spread to other areas quickly- Treatment – anti-fungal cream or orally

with pill

B. Ringworm (not caused by worm)- Skin infection- Same treatment as Athlete’s foot

6. Reproduction:1) Budding (asexual) New individual pinches off parent

2) Spores (sexual)Cells released from parent grow into a new organism

Q) Why was the mushroom at the party so popular?

- Because he was a FUN-GUY (Fungi)

Q) Why did the fungi leave the party?- Because there wasn't mushroom.