Microbiology Exam 2
Are Viruses Living or Nonliving? They are only considered living when they are inside of a host cell, using their
resources and energy.
Outside of a host they are considered intert.
When are Viruses considered to be "alive"? When they are inside of a host cell.
When inside, their nucleic acid (ONLY RNA OR DNA) become active.
*Virus replicates
Obligatory Intracellular Parasites Require livinghost cell in order to multiply - Such as Viruses.
Defining a Virus 1) Contains 1 Nucleic Acid (DNA or RNA)
2) Protein coat surrounds the DNA or RNA
3)Multiply within host using host machinery
---because they don't have the ways of making/obtaining their own nutrients. like
ATP or enzymes.
Virus Characteristics *Some are enclosed by an envelope which consists of lipids, proteins,
carbohydrates
*some have spikes
*only infect the cells of ONE host.
Host Range The spectrum of host cells that a virus can infect.
-invertebrates
-vertebrates
-plants
-protist
-fungi
-bacteria
The virus must be able to attach to a the particular host's cell.
**Host range is determined b specific attachment sites on the host cell's surface
Bacteriophages Bacteria that is infected by a virus
How do Viruses attach to a host cell Through receptors on the host cell's surface.
There must be an interaction.
Capsid Protein coat that surrounds the Nucleic Acid of a virus. (not the whole virus itself.
That's an envelope.)
***Made up of individualized Capsomeres***
*accounts for most of the mass of a viral cell.
Capsomeres Protein subunits that make up a capsid
(think of tiny balls that come together to make a huge coating around the Nucleic
Acid)
*capsomeres can be made up of multiple types of proteins or one single type of
protein
Envelope Surrounds the virus as a whole.
*Synonymus to a somatic cell's Plasma Membrane. But around a virus.
***Composed of proteins, lipids and carbs.
*Could be covered in spikes
NOT ALL VIRUSES HAVE ENVELOPES
, Microbiology Exam 2
Spikes Cover the envelope of the cell
Composed of protein and carbohydrates.
-Used for attachment to the host cell
Spikes differ, and can be identified as different virus by the host body. That's why
you can get the flu more than once a year, there's a change in spikes.
-Can be used for identification for some virsus under microscope.
Helical Capsid Long rods that are flexible and rigid
These surround the Nucleic Acid.
*Capsids are hollow cylinders surrounding the nucleic acid.
*CAN OR CANNOT HAVE A ENVELOPE.
Without envelope = they look like long noodles, because it's just the capsid and
no sphereical shape
WITH the envelope = they look like balls, but with their Nucleic acids all tangled
inside.
Polyhedrical Capsid These are icosahedron, and are 20 triangle shapes, with 12 corners.
THEY CAN BE WITH OR WITHOUT ENVELOPE
-Without envelope, you can see their individual caposomere and their many
different triangular faces of the Capsid
WITH envelope, they appear ordinarily spherical, and like a normal cell. (Some
have spikes)
Complex Capsid They have a variety of weird shapes within the one virus cell, and look just
straight up weird.
They can be bacteriaphages and just look mutuant
Family names suffix for Taxonomy -viridae
Ex. Herpesviridae
Genus name suffix Taxonomy -virus
Genus Simplexvirus
Ex. Herpesvirus
Viral species A group of viruses sharing the same genetic information and ecological niche
(niche=host)
Viral species are designated by descriptive common names, such as human
immunodeficiency virus (HIV),
Subspecies They are determined by the NUMBER that is attached to the specific genus of
the family. These are viruses that can affect humans
HIV-1, HIV-2
Plaque Areas of clearing where the the virus has killed the bacteria
PFU Plaque Forming Unit
*Concentrations of viral suspensions measured by the number of plaques
Cytopathic Effect CPE
This is cell deterioration after a virus infects a monolayer of cells that appears to
be growing just fine.
The cells clump together as they deteriorate.
, Microbiology Exam 2
Virion Complete, fully developed, infectious viral particle composed of nucleic acid and
surrounded by protein coat that protects it from the environment and is a vehicle
of transmission from one host cell to another.
**AKA MATURE PHAGE
Lytic Cycle The cycle that bacteriophages use to multiply.
WHERE THE CYCLE ENDS WITH LYIS AND DEATH OF HOST CELL.
Lysogenic Cycle The cycle that bacteriophages use to multiply.
Where the host cell remails alive after the cycle.
Phage Lysozyme Enzyme released by the bacteriophage tails to break down bacteria cell wall so
they can enter the bacteria.
Lytic Cycle of a T-Even Bacteriophage 1) ATTACHMENT to bacteria cell wall by tail fibers to complementary receptor
sites
2) ENTRY of viron DNA inside the bacteria, and the protein capsid is left outside
of the bacteria cell
3) BIOSYNTHESIS goes underway to use the host machinery to interfear with
host DNA synthesis, and makes the phage DNA instead
4) MATURATION is undergone when capsids are assembled around the DNA,
and the "assembly line" happens to form the virions
5) RELEASE or LYSE happens when the new virions are released to infect other
cells. The host cell does not survive through this cycle.
Prophage The Virus and the bacteria's DNA combined into one.
Oncogene a gene that can bring about malignant transformation
*Also called a cancer causing gene
Pathology Scientific study of disease
"Patho" disease/suffering - Logos "study of/science"
=Concerned with the changes brought by the disease and change it has on the
body.
Pathogenesis The MANNER in which a disease DEVELOPS
Eitology The study of the CAUSE of the disease
Koch's Postulates 1) Same pathogen must be present in EVERY CASE of the disease (aka to be
consistant)
2) Pathogen must be isolated from the disease host and grown in pure culture
3)Pathogens from the pure culture must cause the disease when it is incoulated
into a healthy, suspetible lab animal and then cause disease
4) The pathogen must be isolated from the inoculated animal and must be shown
to be the original organism
- Both organisms infecting both host must match the kind of organism that is
grown and extracted.
Are Viruses Living or Nonliving? They are only considered living when they are inside of a host cell, using their
resources and energy.
Outside of a host they are considered intert.
When are Viruses considered to be "alive"? When they are inside of a host cell.
When inside, their nucleic acid (ONLY RNA OR DNA) become active.
*Virus replicates
Obligatory Intracellular Parasites Require livinghost cell in order to multiply - Such as Viruses.
Defining a Virus 1) Contains 1 Nucleic Acid (DNA or RNA)
2) Protein coat surrounds the DNA or RNA
3)Multiply within host using host machinery
---because they don't have the ways of making/obtaining their own nutrients. like
ATP or enzymes.
Virus Characteristics *Some are enclosed by an envelope which consists of lipids, proteins,
carbohydrates
*some have spikes
*only infect the cells of ONE host.
Host Range The spectrum of host cells that a virus can infect.
-invertebrates
-vertebrates
-plants
-protist
-fungi
-bacteria
The virus must be able to attach to a the particular host's cell.
**Host range is determined b specific attachment sites on the host cell's surface
Bacteriophages Bacteria that is infected by a virus
How do Viruses attach to a host cell Through receptors on the host cell's surface.
There must be an interaction.
Capsid Protein coat that surrounds the Nucleic Acid of a virus. (not the whole virus itself.
That's an envelope.)
***Made up of individualized Capsomeres***
*accounts for most of the mass of a viral cell.
Capsomeres Protein subunits that make up a capsid
(think of tiny balls that come together to make a huge coating around the Nucleic
Acid)
*capsomeres can be made up of multiple types of proteins or one single type of
protein
Envelope Surrounds the virus as a whole.
*Synonymus to a somatic cell's Plasma Membrane. But around a virus.
***Composed of proteins, lipids and carbs.
*Could be covered in spikes
NOT ALL VIRUSES HAVE ENVELOPES
, Microbiology Exam 2
Spikes Cover the envelope of the cell
Composed of protein and carbohydrates.
-Used for attachment to the host cell
Spikes differ, and can be identified as different virus by the host body. That's why
you can get the flu more than once a year, there's a change in spikes.
-Can be used for identification for some virsus under microscope.
Helical Capsid Long rods that are flexible and rigid
These surround the Nucleic Acid.
*Capsids are hollow cylinders surrounding the nucleic acid.
*CAN OR CANNOT HAVE A ENVELOPE.
Without envelope = they look like long noodles, because it's just the capsid and
no sphereical shape
WITH the envelope = they look like balls, but with their Nucleic acids all tangled
inside.
Polyhedrical Capsid These are icosahedron, and are 20 triangle shapes, with 12 corners.
THEY CAN BE WITH OR WITHOUT ENVELOPE
-Without envelope, you can see their individual caposomere and their many
different triangular faces of the Capsid
WITH envelope, they appear ordinarily spherical, and like a normal cell. (Some
have spikes)
Complex Capsid They have a variety of weird shapes within the one virus cell, and look just
straight up weird.
They can be bacteriaphages and just look mutuant
Family names suffix for Taxonomy -viridae
Ex. Herpesviridae
Genus name suffix Taxonomy -virus
Genus Simplexvirus
Ex. Herpesvirus
Viral species A group of viruses sharing the same genetic information and ecological niche
(niche=host)
Viral species are designated by descriptive common names, such as human
immunodeficiency virus (HIV),
Subspecies They are determined by the NUMBER that is attached to the specific genus of
the family. These are viruses that can affect humans
HIV-1, HIV-2
Plaque Areas of clearing where the the virus has killed the bacteria
PFU Plaque Forming Unit
*Concentrations of viral suspensions measured by the number of plaques
Cytopathic Effect CPE
This is cell deterioration after a virus infects a monolayer of cells that appears to
be growing just fine.
The cells clump together as they deteriorate.
, Microbiology Exam 2
Virion Complete, fully developed, infectious viral particle composed of nucleic acid and
surrounded by protein coat that protects it from the environment and is a vehicle
of transmission from one host cell to another.
**AKA MATURE PHAGE
Lytic Cycle The cycle that bacteriophages use to multiply.
WHERE THE CYCLE ENDS WITH LYIS AND DEATH OF HOST CELL.
Lysogenic Cycle The cycle that bacteriophages use to multiply.
Where the host cell remails alive after the cycle.
Phage Lysozyme Enzyme released by the bacteriophage tails to break down bacteria cell wall so
they can enter the bacteria.
Lytic Cycle of a T-Even Bacteriophage 1) ATTACHMENT to bacteria cell wall by tail fibers to complementary receptor
sites
2) ENTRY of viron DNA inside the bacteria, and the protein capsid is left outside
of the bacteria cell
3) BIOSYNTHESIS goes underway to use the host machinery to interfear with
host DNA synthesis, and makes the phage DNA instead
4) MATURATION is undergone when capsids are assembled around the DNA,
and the "assembly line" happens to form the virions
5) RELEASE or LYSE happens when the new virions are released to infect other
cells. The host cell does not survive through this cycle.
Prophage The Virus and the bacteria's DNA combined into one.
Oncogene a gene that can bring about malignant transformation
*Also called a cancer causing gene
Pathology Scientific study of disease
"Patho" disease/suffering - Logos "study of/science"
=Concerned with the changes brought by the disease and change it has on the
body.
Pathogenesis The MANNER in which a disease DEVELOPS
Eitology The study of the CAUSE of the disease
Koch's Postulates 1) Same pathogen must be present in EVERY CASE of the disease (aka to be
consistant)
2) Pathogen must be isolated from the disease host and grown in pure culture
3)Pathogens from the pure culture must cause the disease when it is incoulated
into a healthy, suspetible lab animal and then cause disease
4) The pathogen must be isolated from the inoculated animal and must be shown
to be the original organism
- Both organisms infecting both host must match the kind of organism that is
grown and extracted.
