VIRUSES
Are viruses living or non-living?
non-living
List ONE benefit of bacteria
Digestion. Our large intestines are full of beneficial bacteria that break down food that our bodies can’t digest on their own. Once the bacteria break it down, our intestines are able to absorb it, giving us more nutrients from our food.
Vitamins. Bacteria in our intestines actually produce and secrete vitamins that are important for our health! For example, E. coli bacteria in our intestines are a major source of vitamin K. (Most E. coli is good for us, but there is a harmful type that causes food poisoning.)
Food. Bacteria are used to turn milk into yogurt, cheese, and other dairy products.
Oxygen. Cyanobacteria (which used to be called blue-green algae) live in water and perform photosynthesis, which results in the production of much of the oxygen we need to breathe.
Cleanup. Oil spills, sewage, industrial waste — bacteria can help us clean all of these up! They ‘eat’ the oil or toxins and convert them into less harmful substances.
What language is taxonomy based off?
Latin
What is microbiology?
The study of tiny organisms
Define: incubation
placing an object in a heated environment
What is the lytic cycle? Explain it.
One method for a virus to reproduce
1) Virus recognizes and attaches to a host cell
2) Virus inserts viral DNA (or RNA)
3) Hostile take-over: destroys host cell DNA, and uses viral DNA to make virus protein capsids.
4) Lysis – rupture of cell (host) and release of millions of viruses
Describe 2 morphology of bacteria
A -Bacillus (rod)
B - Coccus (spherical)
C - Spirillum (spiral)
D - Spirochaete (corkscrew)
E - Vibros (comma)
What is a prokaryotic cell?
A Primitive cell with no membrane bound organelles.
Why is aseptic technique so important to maintain when conducting labs?
To stop contamination
Define: agar
nutrient rich medium that allows bacteria to grow
The organism that produces the energy for the virus to reproduce.
AND
Give 2 examples
host
humans and animals
List 3 ways to kill bacteria
-Antibiotics
-Pasteurization
-Disinfectants
-Changing the temp (e.g., very hot or cold environments)
Eukaryotic cells
What does inoculation mean? How does it relate to microbiology?
to introduce microorganisms into environments where they will grow and thrive. In a microbiology lab you will take a sample of bacteria to grow on nutrient agar so colonies will form over time
Define: aseptic technique and why is it important?
technique used in microbiology that prevents contamination by bacteria or other microorganisms.
So you cultivate ONLY the bacteria that you sampled
List 3 ways that viruses can be transmitted.
-Waterborne
-Airborne
-Contact
-Via the placenta
List 4 characteristics of bacteria.
-one-celled, or unicellular, microorganisms.
-can be found anywhere
-can only be seen with a microscope, but they reproduce so rapidly that they often form colonies that we can see.
-Bacteria reproduce when one cell splits into two cells through a process called binary fission
-
What is taxonomy?
the branch of science concerned with classification, especially of organisms
What did we use in the lab to ensure that all equipment was bacteria or germ free before using?
Alcohol wipes
Explain how a vaccine prevents infection
working with the body's natural defenses to safely develop immunity to disease.
Vaccines help develop immunity by imitating an infection. This type of infection, cause the immune system to produce T-lymphocytes and Once the imitation infection goes away, the body is left with a supply of “memory” cells that will remember how to fight that disease in the future. However, it typically takes a few weeks for the body to produce memory cells after vaccination.
List 5 features about a virus
a) can move
b) can respond to stimulus
c) contain complex components
d) can reproduce within a host and kill it
e) has DNA or RNA which is passed onto its “offspring”
f) can’t develop (grow)
g) is not made of cells
h) can’t produce energy on its own. They must use the energy of other cells to “live” and reproduce
i) can’t reproduce without infecting a living thing
j) can die (it is destroyed)
Today, we are witnessing strains of previously controllable infectious bacteria that have become resistant to prescribed drugs. What do we call this?
AND list 2 consequences of this
Antibiotic Resistance.
-hinders our ability to treat infectious diseases and causes more deaths
-Can lead to higher healthcare costs
List the kingdoms of life that we learned about and 1 fact about each.
1. Archaebacteria
-Unicellular
-Live in extreme environments
-Prokaryotic
-(no nucleus)
2. Eubacteria
-Unicellular
-Prokaryotic
-“Common bacteria”
3. Protista
-Eukaryotic
-(has a nucleus)
-Unicellular or colonial
-Lots of different life styles
4. Fungi
-Cell walls made of chitin
-Eukaryotic
-Multicellular
-External heterotrophs (can’t make own food)
5. Plantae
-Eukaryotic & Multicellular
-Cell walls made of cellulose
-Autotrophic
6. Animalia
-Eukaryotic & Multicellular
-No cell walls
-Internal heterotrophs
Describe what products worked the best to inhibit bacterial growth in our lab and how we knew based on our results
-alcohol
-dish soap
-vinegar
List the lines of defense in the immune system and explain
First Line of Defense: External
The human body has many defenses against bacterial infection. The first line of defense is an external, physical barrier. Unless broken, human skin forms an almost impenetrable barrier against bacteria.
Many bacteria enter the body through the nasal passages or the pharynx, both which have defence features. Specialized cells in the lining of these passages secrets mucus that traps the inhaled bacteria.
Bacteria that enter the eyes are attacked by enzymes contained in tears that bathe eye surfaces, cleaning them of bacteria and dust.
Second Line of Defense: The Lymphatic System
Inside the body us a complex network of organs that work to rid the body of infection. These lymphatic organs are connected by a special circulatory system of vessels and nodes. The lymphatic vessels circulate lymph, a transparent fluid containing white blood cells, called lymphocytes, which are produced in the lymph nodes. Lymph nodes are small round masses of cells throughout the body that fight infection. As lymph flows through the lymph nodes and the spleen, microorganisms are filtered out, preventing them from entering the bloodstream and causing infection. If they enter the bloodstream, lymphocytes are transported to body tissues where they act as guards against infection.
When a pathogen invades, internal body defences are activated, beginning with white blood cells called macrophages. Macrophages move and can engulf foreign bodies such as bacteria and destroy them with digestive enzymes.
Third Line of Defense
Antibodies are protein molecules that protect the body from invaders. A foreign material that causes formation of antibodies is called an antigen. Only one specific antibody attaches to an antigen. Antibodies render invaders ineffective, and the antibody-antigen complex provides a signal to macrophages so that these cells can more easily identify and engulf the antigen (e.g., bacterium)