Download microbes cause disease!!

Messana
Science 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
E. Coli
O157:H7 can
make you very
sick.







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
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=4lmwbBz
ClAc
•
•
•
•
•
•
•
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/photobooks/nature/producers-consumers-anddecomposers-3724805

J:\The Parasite Picture Gallery.mht