chapters 20,21,22 microbiology. microorganisms viruses nonliving or living? prokaryotes bacteria...
Post on 19-Dec-2015
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Viruses• Living because they reproduce• Nonliving because…– Require a host aka Parasitic– Replicate instead of reproduce
• Sizes:– Smaller than monerans (Bacteria)
• Almost all organisms have one virus that infects them.
• They are “host-specific” meaning that they will usually only infect 1 organism.
This is what we consider them to be in this class!
Viral Parts• Capsid: outer
protein coat• Genetic Material:
DNA or RNA• Envelope:
Protective layer around the capsid.– NOT ALL VIRUSES
HAVE THESE– Comes from the
host cell membrane
Types of Viruses
• DNA Viruses– Has DNA as
Genetic Material
Single-stranded DNA virus:
Canine Parvovirus
Double-stranded DNA virus:
Chicken pox (Varicella zoster)
DNA Viruses
Herpes Virus in a host cell
Human Papilloma virus: causes warts
Adenovirus: causes some colds
RNA viruses
Paramyxovirus: Measles and Mumps (in a host cell)
Rabies virus
Rhinovirus: Common ColdHas RNA as Genetic
Material
Types of Viruses
• Retroviruses- RNA as genetic material.– To replicate, they convert RNA to DNA
and then use host to make more RNA.
HIV (Human immunodeficiency virus)
Characteristics of Bacteria (Monerans)
• All are prokaryotic• All have a cell wall• All have DNA as genetic material• All have ribosomes, and no other
organelles• All are unicellular• Most are heterotrophic (not all!), some
are chemo or photo-autotrophic
Fungus Characteristics
• Eukaryotes• Heterotrophic
decomposers– Saprophytes,
parasites, predators, mutualistic
• Non-motile
• Cell walls of chitin• Most have hyphae that into tangled
masses called mycelium• Growth occurs rapidly at tips
General Characteristics of Protists
• Have a nucleus• Are grouped based on the method of
locomotion– Cilia– Flagella– Pseudopods– Non-motile
Viral
• Cystic fibrosis treatment
• Tulip colors• Treat
bacterial diseases ***
• Genetic engineering ***
Bacteria
• Fix nitrogen• Decomposer• Food
production• Sewage
treatment• Antibiotics• Genetic
engineering
Fungus
• Mutualism• Decomposer• Antibiotics• Fermentation• Food
production
Protists
• Producers in water
• Oxygen production
Microorganism benefits
Viral
• Disease• Cancer
Bacteria
• Disease• Spoilage
Fungus
• Disease• Spoilage
Protists
• Disease• Algal
blooms
Microorganism disadvantages
What do microorganisms need?
• Each species has an OPTIMUM– Temperature– pH– Air– Osmotic Pressure–Water– Nutrients
How can we prevent them from getting these requirements?
• Heat• Change pH• Add salt or sugar• Remove oxygen (canning)• Remove water by
Dehydrating foods
How do we spread diseases and how do we stop them?
• Five methods for spreading disease.– AIR– FOOD–WATER– PERSON to PERSON– VECTORS- insects
How does an infection makes us sick?
• What they do: Grow and Reproduce– Destroys cells– Release toxins– Block passages
• What we do: – Crummy Article
Germ Theory of Disease 1857
Louis Pasteur• Eliminates theory of spontaneous
generation• Saves the wine Industry in France• Proposes that there is a relationship
between a microorganism (pathogen) and a disease
• Develops– Pasteurization– Vaccines for anthrax and rabbies
Koch’s Postulates 1876
Find suspect organism
Isolate suspect and grow in pure culture
Inject pure culture into healthy subject and get the same disease symptoms
Re-isolate the same suspect organism and grow it in pure culture
Vaccines:
• Treatment for viruses
• Taken as a preventative method
• Cannot help you once you have the disease
• Viruses can become resistant to these, but it is not usually a fast process
• Human production
Antibiotics:
• Treatment for bacterial infections
• Taken once you have the disease
• Cannot be used as a preventative
• Bacteria can easily become resistant to these
• Bacteria and some fungi produce these
Vaccines
• Involves your immune system being stimulated
• Dead or weakened antigen (foreign particle)• Engulfing cells and antibody producing cells
destroy the antigen• Memory cells prepare for another infection– Response to virus is faster and stronger the
second time
• Adds to the health of the community
Antibiotics
• Work ONLY on bacteria– Bacteria are prokaryotic, we are eukaryotic– Bacteria have a cell wall, we do not.
• These help, but our immune system still has to “clean-up”
• Examples:– Penicillin – stops cell wall
formation– Tetracycline – stops protein synthesis– Ciprofloxacin – stops DNA replication
Proper use of antibioticsPrevents Resistance
Only taking them for bacterial infections
Taking pills on time
Taking all your prescription
Concentration of Bacteria at which you feel better =====
Time in DaysShot of Penicillin-Pill taking intervals – missed interval
Concentration of antibiotic -
Effective concentration of antibiotic ---
Concentration of bacteria ……C
on
cen
trati
on
Antibiotic Resistance
• Development of Resistance– Alter the antibiotic– Alter the target or structure– Pump out the antibiotic
• Developing new anti-resistance antibiotics– Target the mechanism that confers resistance
• Stop alteration of antibiotic• Stop alteration of target• Stop the molecular pumping mechanism
Stop the Spread of antibiotic resistance
Do not demand antibiotics
Take them exactly as prescribed
Wash fruits and vegetables(no such thing) thoroughly; avoid raw eggs and undercooked meat, especially in ground form
Use soaps and other products with antibacterial chemicals only when protecting a sick person whose defenses are weakened
The BIG picture
• Diet• Rest• Exercise both aerobic and resistance
• Personal Cleanliness e.g. wash your hands
• Proper Preparation and storage of food– It Must Have Been Something You Ate
• Environmental Cleanliness pollution, filth
• Annual Physical