Virus Review!Virus Review!

1.1.What are the two main parts that What are the two main parts that make up the structure of a virus?make up the structure of a virus?

2.2.What is the difference between an What is the difference between an active and a hidden virus?active and a hidden virus?

3.3.What is the term used to describe What is the term used to describe the chemical that prevents viruses? the chemical that prevents viruses? How does it actually work?How does it actually work?

4.4.The influenza of 1918 is known as, The influenza of 1918 is known as, “one of the worst pandemics the “one of the worst pandemics the world has ever known.” What do world has ever known.” What do think a pandemic is?think a pandemic is?

BacteriaBacteriaPages 217-225

Two Domains/Two Kingdoms

• KINGDOM Archaebacteria– Live in extreme

enviroments• Water as hot as 110°C• Acidic as lemon juice• Intestines, mud, and

sewage

– Produce foul odors

• KINGDOM Eubacteria– DO NOT live in

extreme enviroments– Live everywhere else

• Coat your skin• Swarm in your nose

– Most are either useful or harmless to you

DOMAINS: 1. Archaea 2. Bacteria 3. Eukarya

Bacteria• HISTORY: Anton van

Leeuwenhoek found bacteria first in teeth scrapings

• STRUCTURE:

single celled prokaryotes– DNA floats in cytoplasm

(no nucleus)– Ribosomes; no other

organelles

Three cell shapes

• Rodlike(Phylum Bacilli)

• Spherical (Phylum Cocci)

• Spiral Shaped (Phylum Spirilli)

Phylum CocciStreptococcus aureusCauses Strep Throat

Staphylococcus aureusCauses staph infections

Neisseria gonorrhoeaeCauses a sexually transmitted disease called gonorrhea

Phylum Bacilli

Escherechi coliCauses food poisoning

Bacillus anthracisCauses anthrax, can grow in aerobic OR anaerobic environments Bacillus thuringiensis

A bacterium found in soil that keeps away insects.

Phylum Spirilla

Borrelia burgdorferiFound in intestines of ticks, carries Lyme disease

Treponema pallidumCauses the sexually transmitted disease, syphilis. Spirillum minus

found in rodents causes rat bite fever in those people who come in contact with infected rats

How do Bacterial Cells Move?

• Flagellum – a long whip-like structure that moves the cell like a propeller.

• May also have tiny protein fibers called pili.

• Most bacteria without flagellum cannot move on their own and must rely on other things to move them.

Two Types of Reproduction• Sexual Reproduction – involves two parents who

combine their genetic material to produce a new organism, which differs from both parents. – Conjugation – one bacterium transfers some of its genetic

material to another bacterium through a thin, threadlike bridge that joins the two cells

– The term sexual reproduction is loosely used here. There is an exchange of DNA, however no NEW cells are created.

A pilus bridges from one cell to the other

Two Types of Reproduction• Asexual Reproduction – reproductive process that

only involves one parent and produces offspring that are– Binary Fission – process by which one cell divides to

form two identical cells. A form of asexual reproduction.

identical to the parent.

Stages of Bacterial Growth• LAG PHASE: Growth is slow at

first, while the microbes acclimate to the food and nutrients in their new habitat.

• LOG PHASE: Once used to the environment, they start multiplying exponentially, doubling in number every few minutes.

• STATIONARY PHASE: As more and more microbes are competing for dwindling food and nutrients, booming growth stops and the number of bacteria stabilizes.

• DEATH PHASE: Toxic waste products build up, food is depleted and the microbes begin to die.

Lag

Getting Food

• Some bacteria are autotrophic and make their own food. – They can use the sun’s

energy the same way plants do (photosynthesis), or they can use chemical substances in their environment to make food (chemosynthesis).

• Other bacteria are heterotrophic. They get their food by eating autotrophs or other heterotrophs.

Respiration

• Like many other organisms most bacteria need oxygen to break down their food to get energy. (AEROBES)

• A few kinds of bacteria do not need oxygen, and it is actually like poison to them. (ANAEROBES)

An anaerobic bacteria found in soil

Is All Bacteria Bad?• Bacteria is not all bad. There are several ways

in which Bacteria is helpful. 1. Involved in fuel and food production

2. Environmental recycling and cleanup.

3. Decomposers - break down large chemicals in dead organisms into small chemicals

Illness and Health

• Some bacteria can make you sick.

Bacterial diseases can be passed in many ways. – Direct contact, like touching, hugging, or kissing. – Indirect contact, such as inhaling drops of moisture, or

sharing food and drink. – Who has a cell phone?

Treatment?• Bacterial diseases are treated with antibiotics,

such as penicillin, and amoxicillin. – A chemical that can kill bacteria without harming a

person’s own cells.

• You also have bacteria in you digestive system to help break down food.

Bacteria Review