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Virus Videos Zika Virus: What we know and don’t know
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Microbiology: Bacteria Basics
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Objectives: By the end of the lesson you should be able to:
State the classification of bacteria and why Describe the structures of bacteria Describe the form and arrangement of bacteria
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Introduction The prokaryotes are found almost everywhere on Earth - they live anywhere that life can physically survive They are essential to life - their importance cannot be overestimated They also cause some of our major diseases
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Taxonomy Recall that there are 3 domains:
Bacteria: prokaryotic cell; “regular” bacteria Archaea: prokaryotic cell; ancient bacteria, live in extreme conditions Eukaryota: eukaryotic cell
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Domain Bacteria Kingdom Eubacteria
Bacteria are very small cells; just visible with a light microscope Clostridium tetani: causes tetanus! One of the most potent biological toxins that affects humans
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Kingdom Eubacteria General structures:
A cell wall (not like a plant! It’s made out of peptidoglycan not cellulose!) A plasma membrane (protective layer, decides what goes in/out) Cytoplasm (“jelly”) A free floating chromosome of DNA Ribosomes (make proteins)
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Other Structures: Plasmid
A small circular piece of DNA separate from the chromosomal DNA which can replicate independently.
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Other Structures: Flagella
Used for movement Causes cholera Causes a feverlike illness Causes infections Type of food poisoning
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Other Structures: Pili
Used for attachment to solid surfaces, in transfer of DNA from one cell to another, small movements and cell-cell adhesion
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Other Structures: Capsule
These are non-protein thick protective coats outside of a bacteria cell
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Other Structures: Spores
Spores are tough coated structures that contain a complete bacteria chromosome Spores can remain dormant waiting for more favourable growth conditions Clostridium botulinum bacteria. The bacterium produces a nerve toxin that causes botulism.
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Other Structures: Spores Cont’d (Not in your notes)
They can tolerate extreme dryness. Some cannot be killed even at subzero temperatures. Some can spread poisonous chemicals Bacterial spores are extremely resistant. Spores of tetanus and anthrax, for example, can survive in the soil for many years.
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Typical Prokaryotic Cell
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Form and Arrangement Form: the shape of the bacteria
Arrangement: how the bacteria are arranged spatially
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Forms and Arrangement Cell form (shape) is a sphere ARRANGEMENTS:
1. Coccus Cell form (shape) is a sphere
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Forms Rods True Bacillus 2. Bacillus Cells are longer than wide (rods); typically solo, in pairs or chains
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Forms 3. Spirillum Longer than wide and curved
Most are pathogens and in a single arrangement
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On the News! Bacteria Video:
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5 Things you should know about bacteria
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No deodorant? Try hand sanitizer
“Deodorants will only have a short-term effect. Anti-perspirants actually affect your skin, not the microbes. Lowers the number of microbes
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Germs can make you gain weight
If you think using artificial sweetener will help you lose weight, think again Bacteria like food, you’re giving something that’s not food. They get upset. And when they get upset, they release toxins. Feedback system causes body to store energy in the form of FAT
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Washing your clothes in cold water doesn’t kill germs
So how do you kill stinky bacteria without killing your clothes? Put them in your freezer. bacteria have a hard time surviving when temperatures dip below -10°C, which is the standard temperature of a residential freezer
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You could be brushing your teeth with bits of feces
if you don’t close your toilet lid before you flush, little particles of feces float up into the air and land on your bathroom surfaces — like your toothbrush. It helps to run your toothbrush under hot water for five seconds before you put it in your mouth, as well.
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No puppy love for your newborn
A dog’s mouth has less microbes than a baby’s mouth, research has shown. That still doesn’t mean a dog should be allowed to lick an infant under the age of six months. Newborns don’t have an immune system that’s strong enough to handle all that bacteria, he says.
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