MessanaScience 8

Chapter 25

= Microorganism, Microscopic Organism Bacteria Virus Parasite Fungi Found EVERYWHERE!!...water, surface

of living things, inside living organisms

Caused by a microbe entering a place in the body where they aren’t supposed to be

Organism experiences impaired function Show symptoms = your body’s response

to disease (fever, vomiting, joint pain, skin condition, diarrhea, etc.)

Can be infectious/communicable OR non-infectious/non-communicable

Bacteria

Single celled organisms – ALIVE! Very small, Need microscope to see Prokaryotic Can be found on most materials and surfaces –

Soil, Water, Air, etc. Can live: With/WO O2, extreme HOT/COLD.

Bacteria doubles, reproduces VERY quickly :0

Billions on your skin and in your body’s digestive track right now!

Alexander Fleming~ 1928…accidentally grew mold; led to discovery of PENICILLIN!!

Harmless bacteria on the stomach lining

E. Coli O157:H7 can make you very sick.

Streptococcus can cause strep throat.

Different shapes = sphere, rod, spiral Have cell membrane, cell wall, &

capsule Cytoplasm contains genetic material

floating freely + ribosomes (no nucleus or other organelles)

Has flagellum & cilia Can move, reproduce, eat, etc.

Harmful Bacteria = Germs, Pathogens (Greek: Pathos ~ means “suffering”)◦ Cause disease by releasing toxins into body◦ Toxins are the waste products from bacteria◦ Bacterial infections fever, swelling, rash◦ Treat with ANTIBIOTICS! Antibiotic resistance

occurs when antibiotics are OVERUSED!! Helpful Bacteria: (ex. found in intestines)

◦ Eat other more harmful substances◦ Help plants and animals release nutrients to be

used by organism◦ Digest food in your stomach

: //www.youtube.com/watch?v=3xRttWuf3wQ

http://www.youtube.com/watch?v=4lmwbBzClAc

• VERY small!• Composed of DNA or RNA &• protein coat = CAPSID• NOT A LIVING CELL!!• Can’t reproduce, eat, move, or

maintain homeostasis• Must get inside HOST CELL to reproduce• Must fit cell membrane like “lock and key”

If virus finds suitable living host cell…uses the enzymes & organelles of host cell to make more viruses◦DNA or RNA directs host cell to make copies of virus particle

◦Copies of virus cause host cell to EXPLODE!

◦Viruses go on to affect other cells

Youtube.. Virus (HPV)

• Cause disease in plants & animals• Viral diseases are the most widespread

illnesses in humans…minor as fevers…serious as some forms of cancer

• Transmitted: human contact, water, food, insect bites…

• Can’t treat viral infections with anything – have to run their course..

• HOWEVER~ some vaccines & anti-viral drugs used to control & prevent spread of disease (HIV/AIDS, Herpes/Shingles – Valtrax)

YouTube… Virus Rap!

An organism that has a harmful relationship with a host organism

Parasite lives on or in the host Slowly weakens or kills host quickly Usually SPECIALIZED ANATOMICALLY

(structure of the organism) & PHYSIOLOGICALLY (function of the organism).

EX: Tapeworms-so specialized = NO digestive system. Live in small intestine & absorb food directly through skin :0

EX: lice, ticks, heartworm, mites, fleas, pin worms, tapeworms… Tapeworms are flatworms that consist of a head, neck and a segmented

body that can grow up to 20-30 feet long with hooks on the underside to attach to intestinal walls. :0 Tapeworm infection can be caused by ingesting tapeworm eggs or larvae, which can be found in animal meats, water, soil or animal feces

PREVENTION: Wash hands!!! Cook meat! Sanitize Water!!

Are you ready for these pictures!?

The Parasite Picture Gallery - Life cycles of several very common parasites.htm

9 Human Parasites You Don't Want Along for the Ride Page 3 TreeHugger#slide-top.htm

Transfer sun energy into energy that can be used by cells

Break down materials in

Dead/Decaying organisms

for reuse.

http://www.mixbook.com/photo-books/nature/producers-consumers-and-decomposers-3724805

J:\The Parasite Picture Gallery.mht