31.1 Pathogens and Human Illness

Sponge- Pg 44

1. Hypothesize what you think the white blood cell is doing in this picture.

2. Hypothesize why you do not get sick EVERYTIME disease causing germs invade your body.

White blood cell

E. Coli (bacteria)

31.1 Pathogens and Human Illness

Sponge

1. Hypothesize what you think the white blood cell is doing in this picture?

The white blood cell is attacking the invader

2. Hypothesize why you not get sick EVERYTIME disease causing germs invade your body?

The white blood cells attack and destroy invaders before you get ill. They protect you.

White blood cell

E. Coli

31.1 Pathogens and Human IllnessSet up Cornell Notes on pg. 45•Topic: 31.1 Pathogens and Human Illness

•Essential Question(s):

1.On pg. 44 please create a double-bubble map, comparing and contrasting viruses and bacteria using the book, notes, and videos, and REAL LIFE examples of each.

2.1 Atoms, Ions, and Molecules

31.1 Pathogens and Human Illness

31.1 Pathogens and Human Illness

KEY CONCEPTGerms cause many diseases in humans.

31.1 Pathogens and Human Illness

• Diseases caused by germs, such as the E. Coli bacteria can be fatal (death)

• 1330-1352, the bacteria that caused the “Black Death” or the Plague originated from fleas on rats

– Killed approx.

100-200 MILLION

people

– New diseases- HIV- SARS- Avian Flu (bird flu)- Swine Flu

31.1 Pathogens and Human Illness

• Germ theory proposed that microorganisms cause diseases.– led to rapid advances in understanding disease– Can be infectious (polio, flu), caused by germs– or noninfectious (cancer, heart disease), caused by

genes or lifestyle

31.1 Pathogens and Human Illness

• Disease-causing agents are called pathogens.• What would happen if pathogens were eliminated?

– We wouldn’t get sick

31.1 Pathogens and Human Illness

There are different types of pathogens.

• Bacteria are single-celled organisms. – cause illness by destroying

cells – release toxic chemicals– Can be treated/killed with

antibiotics or antiseptics

– Exs: – E. Coli– Salmonella – “Food Poisoning”

31.1 Pathogens and Human Illness

• Viruses are disease-causing strands of DNA or RNA that are surrounded by a protein coat.

– Take over a healthy (host) cell – Forces cells to produce more of the virus – Smaller than bacteria– Can be prevented with vaccines

– Exs:– HIV

– Influenza

– Herpes– *Common Cold– AIDS

31.1 Pathogens and Human Illness

• Fungi can be multicellular or single-celled.

– take nutrients from host’s cells– occur in warm and damp places

Ex: Athlete’s foot, yeast, mold

31.1 Pathogens and Human Illness

• Protozoa are single-celled organisms

– Prey on other cells– use host cells to complete their life cycles– take nutrients from host cell

– Ex: Malaria, dysentery

31.1 Pathogens and Human Illness

• Parasites are multicellular organisms.

– grow and feed on a host – possibly kill the host

Ex: Heart worm Round worm Elephantiasis- mosquitos

31.1 Pathogens and Human Illness

• Vectors any person or animal that carries and transmits a pathogen to another living organism.

• Direct contact requires touching an infected individual. Includes: – kissing– sexual intercourse – hand shaking – bite

tickEx:Lime Disease- ticksMalaria- mosquitoWest Nile Virus- mosquitoRabies- rabid animalHIV- infected person

31.1 Pathogens and Human Illness

Pathogens can enter the body in different ways.

• Direct contact require an infected person or animal to physically touch a healthy person • Ex: Rabies, HIV

• Indirect contact does not require touching an infected individual. • Ex: SARS, TB

31.1 Pathogens and Human Illness

• Different pathogens cause common infectious diseases.

31.2 Immune System

Classwork/Homework

On pg 44 please draw a double-bubble map comparing and contrasting bacteria and viruses (pg. 942 & notes & Videos)

31.1 Pathogens and Human Illness

Viruses vs. Bacteria Videos

Viruses•Viruses•How Viruses Work•The Influenza Pandemic of 1918

Bacteria•Bacteria•Beneficial Bacteria•Harmful Bacteria

• Add notes on the videos to your Double-Bubble Map

Focus:• How viruses use our cells against us• Beneficial bacteria vs. Harmful bacteria

31.1 Pathogens and Human Illness

Beneficial Bacteria• Decomposers

– Break down dead material

• Soil– Makes it fertile so plants can

grow

• Intestines– Aids in digestion– Produces vitamins

• Food– Cheese, sour cream, yogurt

• Medicine-

– help fight diseases

• Sewage Treatment• Oil spills

Harmful Bacteria

• Take over ponds, etc.– Kills existing life

• Food– Grows on food (spoils)

• Mouth– Feed on food in between

teeth- Must brush and floss

• Infect– Open sores

• Difficult to kill– May have a slippery outer

capsule

31.2 Immune System

Single- celled

Release toxic chemicals

Larger than viruses

E. Coli

Pathogens

microscopic

Infectious

Have a protein coat

Force cells to produce more

virus

Smaller than Bacteria

HIV

Common cold

FluBacteria Viruses