Microbiology
Part II Bacteria and Viruses
Bacteria
There are two main types of Bacteria
Eubacteria “______” are found
______, in the air, on the ground, and in water,
even on the page you’re writing now.
Archebacteria “______” are found only in ______,
for example, places that are intensely hot (sulfur pools, ocean vents), salty (Dead Sea), or acidic (inside digestive tract).
Most Bacteria are much ______than plant and animal cells.
They are ______. This means they have no nucleus… all the genetic material is just strewn around loose in the cell.
Bacteria do contain ______to manufacture protein.
Some bacteria also contain the pigment ______and are autotrophs, able to produce their own food through ______.
Some other autotrophic bacteria can use ______in their environment to produce their food (______).
Most, however, are ______consuming a variety of foods, breaking down dead material or living as parasites off a host.
Almost all organisms on earth including most bacteria ______to break down food and release energy- they are called ______
Some bacteria, however, are adapted to live completely ______and are called ______. These are usually found buried deep in ______or bogs, in ______in the ocean, or even in the ______!
Bacteria in Nature and Industry
Bacteria are involved in:
______and food production
Environmental ______and cleanup
In health maintenance and ______production
Bacteria in Nature and Industry: Oxygen Production
Autotrophic bacteria use the sun's energy to produce their food and as a result they ______into the air.
Scientists believe autotrophic bacteria were responsible for adding oxygen to the Earth's ______and made it habitable for life as we know it.
Today, distant ancestors of those bacteria continue to keep oxygen levels in the air stable
Bacteria in Nature and Industry: Food Production
The activities of helpful bacteria help produce many foods, like ______, sauerkraut, ______,
apple cider and ______.
Bacteria that grow in milk help produce ______
products such as buttermilk, ______, sour cream and ______
Some bacteria however cause food to ______when they break down the food’s chemicals.
______&______can slow down spoilage
Another method to preserve food is called ______
Named after its inventor, Louis Pasteur, it involves heating food to a temperature high enough to ______without changing the flavor of the food.
Bacteria in Nature and Industry: Environmental Recycling
Some heterotrophic bacteria that live in soil are ______, -organisms that break down large chemicals in dead organisms into smaller chemicals
For example, decomposing ______in the fall and winter so the nutrients can be ______by the plants in the spring
______bacteria live in the soil
and in nodules in the roots of a type of plant called a legume (like
peanuts, soy beans and peas)
These helpful bacteria help plants by ______
from the air into a form of nitrogen plants need to survive.
Without nitrogen-fixing bacteria, farmers would need to spend millions
more on ______each year.
Bacteria in Nature and Industry: Bio-remediation (Environmental Clean-up)
Some bacteria can ______.
They can convert the poisonous chemicals in oil into ______substances.
Scientists use them to help ______in oceans and gasoline leaks in soil under gas stations.
Bacteria and your health: ______Bacteria
There are many bacteria in your body that help keep you
______
In your digestive system your ______
teem with bacteria.
Some help you ______
Some make vitamins like ______that your body needs
Others compete for space and resources with disease causing organisms, keeping harmful bacteria from attaching to your intestines, making you sick.
Viruses
A virus is a tiny ______that enters and then reproduces inside a living cell.
No organisms are safe from viruses, for every different type of cell in every different type of organism; there is a virus able to ______that organism's cells.
Viruses come in many shapes
All viruses have two basic parts: a ______that protects the virus and an inner core made of ______
Some viruses are surrounded by an additional covering called an ______
Each virus contains specific ______.
They are shaped to match a particular host cell
This explains why each virus has very ______that it is able to infect.
Viruses: How they multiply
Viruses are considered ______ because
they do not show all the characteristics of life.
They are not cells and do not use their own energy to grow or respond to
their environment
Although viruses can multiply, they do so differently than organisms.
Viruses can multiply only inside a living ______
A virus acts like a ______, as almost all
viruses destroy the cells in which they multiply.
Once inside a host cell, a virus's ______
takes over many of the cells functions.
It ______a cell to produce the virus's proteins genetic material.
These then ______into new viruses ready to infect more host cells.
Viruses: How they multiply- Active and Latent Viruses
______ begin production and assembly
immediately.
Making copy after copy of the viruses until the host cell ______and new viruses begin
infecting neighboring cells.
Hidden or ______viruses do not affect
the cell right away.
The virus genetic material ______of the cell's
genetic material.
Each time the host cell divides, the virus genetic material is ______along with the host material.
Then under certain circumstances, the virus's genetic material suddenly becomes active and ______begin producing copies of the virus.
Viruses in medicine
Not all news about viruses is bad.
______ takes
advantage of a virus's ability to enter a host cell
Scientists ______harmful virus
genetic material with good genetic material
They then use the virus as a messenger service to deliver genetic material to cells that need it.
Bacteria, Viruses and your health
How Infectious diseases are spread:
Through contact with an ______
A contaminated object
An infected animal
An environmental source.
Once contact occurs disease-causing agents may enter through:
______in the skin
May be inhaled or swallowed
May enter the ______of the eyes, nose, mouth or other body openings.
Treating Infectious Diseases- Bacteria
Luckily, many bacterial diseases can be treated with antibiotics.
An ______ is a chemical that will destroy bacteria (usually by
weakening the cell wall causing the bacterial cells to burst) without harming a person's cells
Unfortunately, some bacteria are becoming ______. As resistant bacteria survive and reproduce the number of resistant bacteria increases.
Today some bacterial diseases are becoming very difficult to treat.
Treating Infectious Diseases-Viruses
Unlike bacterial diseases there are currently ______
that cure viral infections.
There are many ______medicines that
can help a person feel better
The best treatment for a virus is usually ______.
Although there is no cure for a virus, a ______ may be able to prevent a person from getting sick in the first place.
A vaccine stimulates the production of chemicals that ______or bacteria.
A vaccine may be made from ______viruses or bacteria. Therefore it will not cause a person to become sick.
Instead the vaccine will activate a person's ______putting the body “on alert”.
So that if the virus or bacterium ever invades the body it is destroyed by ______before it can cause the disease.