Download MICROBES CAUSE DISEASE!!

Messana
Science 8
Chapter 25
MICROBES
 = Microorganism, Microscopic Organism
 Bacteria
 Virus
 Parasite
 Fungi
 Found EVERYWHERE!!...water, surface of living
things, inside living organisms
DISEASE
 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
infectious/non-communicable
non-
Youtube….
 Bacteria
 https://www.youtube.com/watch?v=kxM_9DL2GYw
BACTERIA
 Single celled organisms – ALIVE!
 Very small, Need microscope to see
 Prokaryotic
E. Coli
O157:H7 can
make you very
sick.
Harmless bacteria on
the stomach lining
 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!!
Streptococcus can
cause strep
throat.
BACTERIA
 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.
Typical Bacterial Cell
Helpful vs. Harmful Bacteria
 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
Clean skin has about 20 million
bacteria per square inch
Youtube
:
 //www.youtube.com/watch?v=3xRttWuf3wQ
 http://www.youtube.com/watch?v=4lmwbBzClAc
Viruses
• 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”
Virus
Replication
 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
Virus invading Bacterial Cell
 Youtube..
 https://www.youtube.com/watch?v=kYf_Sl8W3qY
 Virus (HPV)
 https://www.youtube.com/watch?v=sHxm3crp4Yk
Viruses
• 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!
 https://www.youtube.com/watch?v=kYf_Sl8W3qY
Parasites
 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
Parasites….
 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!!
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A
re you ready for these pictures!?
A
Parasites
Fish Parasite & Blood Parasite