Weebly · Web view-The viruses that infect bacteria are called _____ and they have two types of...
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Name: Date: Microbiology: Viruses Learning Outcomes: 1. Evaluate the evidence used to classify viruses as living or non-living 2. Evaluate the effects of viruses on human health Text: 181 to 183, 200 to 203. *This is required reading. Introduction to Viruses -Viruses are not cells, so they are not placed in any of the kingdoms of living organisms. -They are composed of a _________ _____________ core of either DNA or RNA, and a ______ _________ coat called a capsid. They may have an envelope composed of a membrane from their host combined with viral glycoprotein. -Bacteriophages have a more complex structure. They attack bacteria cells. (p.182) -Viruses are ________ _____________ on living cells. Viruses are specific to a particular __________________________. -Viruses are very small. They are 2 to 0.2 micrometers in size. This is comparable to a large protein molecule. Biology 11: Viruses Page 1
Transcript of Weebly · Web view-The viruses that infect bacteria are called _____ and they have two types of...
Name: Date:
Microbiology: VirusesLearning Outcomes:
1. Evaluate the evidence used to classify viruses as living or non-living
2. Evaluate the effects of viruses on human health
Text: 181 to 183, 200 to 203. *This is required reading.
Introduction to Viruses
-Viruses are not cells, so they are not placed in any of the kingdoms of living organisms.
-They are composed of a _________ _____________ core of either DNA or RNA, and a
______ _________ coat called a capsid. They may have an envelope composed of a membrane
from their host combined with viral glycoprotein.
-Bacteriophages have a more complex structure. They attack bacteria cells. (p.182)
-Viruses are ________ _____________ on living cells. Viruses are specific to a particular
__________________________.
-Viruses are very small. They are 2 to 0.2 micrometers in size. This is comparable to a large
protein molecule.
-Illustrated below are a few different viruses.
Biology 11: Viruses Page 1
*See some creative Virus artwork at the Met:
http://www.mymodernmet.com/profiles/blogs/luke-jerram-glass-microbiology
-The diagram below is of a typical influenza virus. It belongs to a type of viruses that
are surrounded by a membrane envelope.
-Label: RNA, protein coat, membranous envelope and glycoprotein spike.
-How do enveloped viruses get their envelopes? How are the envelopes useful?
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Biology 11: Viruses Page 2
Are Viruses Alive?
Comparison of Virus and Bacteria Traits
Characteristics of Life Bacteria Viruses
Possesses Nucleic Acid
Consists of a Cell
Metabolism
Respond to Stimuli
Multiply
Evolve
-Viruses have some of the properties of living organisms, but depend upon their host cells for
most functions. They are obligate parasites because:
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Viral Reproduction
-A virus can only replicate by using the enzymes, ATP, ribosomes and tRNA of its host. How
are these molecules useful?
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Biology 11: Viruses Page 3
-View Activity: Simplified Reproductive Cycle of a DNA Virus (10.18) from the text
website and use the information there to label the main steps of the life cycle of a virus on
the diagram below. You must also read text page 201 carefully.
Bacteriophage Life Cycles (Text 182)
Biology 11: Viruses Page 4
-The viruses that infect bacteria are called
_________________________________________ and they have two types of life cycles
(or two parts to their life cycle).
View Activity: Phage T2 Reproductive cycle (10.1) on the text website and use this to understand
the bacteriophage life cycle.
Retroviruses (Text 498 to 499)
-View Activity: Retroviruses(HIV) Reproductive cycle (10.20). Use the information
found here to describe what retroviruses are.
Biology 11: Viruses Page 5
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-Which modern, devastating disease is caused by a retrovirus?
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-What is the virus called? ___________________________________________________
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-Review Processes of Science: What cause infections in AIDS patients? (10.20) from the
text website.
-Why do AIDS patients become infected with
other diseases so easily? (p.498)
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The History of AIDS (http://fohn.net/history-
of-aids/ )
-Read the quote from an article about the history of AIDS.
“While the origin of the AIDS epidemic has been clarified, an explanation for why the
epidemic arose in the mid-20th century, and not before, remains a matter of speculation."
Chimpanzees are frequently hunted for food, especially in West-Central Africa, and we
believe that HIV-1 was introduced into the human population through exposure to blood
during hunting and field dressing of these animals," says Hahn. She further believes that
while incidental transmissions of chimpanzee viruses to humans may have occurred
throughout history, it was the socio-economic changes in post-World War II Africa that
Biology 11: Viruses Page 6
a) Tobacco Virus; b) Pea Mosaic Virus
provided the particular circumstances leading to the spread of HIV-1 and the
development of the AIDS epidemic. "Increasing urbanization, breakdown of traditional
lifestyles, population movements, civil unrest, and sexual promiscuity are all known to
increase the rates of sexually transmitted diseases and thus likely triggered the AIDS
pandemic," adds Hahn.
-Another type of animal disease caused by a virus is Mad Cow Disease. This disease is
caused by a type of virus called a prion, which is a misfolded protein that cases normal
proteins inside of brain cells to also misfold. In doing so, it causes the brain and spinal
cord to deteriorate and affects the cow’s behaviour and nervous system.
-Can you think of any other animal diseases caused by viruses?
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Plant Viruses and Viroids
Plants can also be affected by viruses. One type of plant
virus is called viroids:
-Viroids are small circular RNA molecules that use plant
cell enzymes to replicate themselves.
-Viroids cause errors in the system controlling plant growth.
*Complete the Development of Virology Lab to learn more
about plant viruses.
Biology 11: Viruses Page 7
