Download Holly gets sick

DO NOW….
Draw a square on your paper.
Draw a triangle around the square.
Draw two different types of antennae extending from the triangle.
Draw several swiggly lines within the square.
HOLLY GETS SICK
A Story about Fighting the Flu
FLU VIRUS STRUCTURE
Picture A
Influenza Virus
Your drawing and picture A represent a virus. Align the
Parts you drew with the name of real virus parts from A.
WHAT ARE
VIRUSES?
A virus is a non-cellular
particle made up of
genetic material and
protein that can invade
living cells.
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SIZE OF VIRUSES
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CHARACTERISTICS
1. Non living structures: not a cell
2. Contain a protein coat called the
capsid
3. Have a nucleic acid core containing
DNA or RNA
4. Capable of reproducing only when
inside a HOST cell: pseudoparasite
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CHARACTERISTICS
1. Some viruses are enclosed in CAPSID
an protective envelope
DNA
2. Some viruses may have
spikes to help attach to the
host cell
3. Most viruses infect only
SPECIFIC host cells
For some viruses, the capsid is surrounded by lipid
bilayer that contains viral proteins, usually including
the proteins that enable the virus to bind to the host
cells. This lipid and protein structure is called the
virus envelope, and is derived from the host cell
membranes.
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ENVELOPE
SPIKES
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CAPSID STRUCTURE
•
•
Viral capsids
(coats) are made
of individual
protein subunits
Individual
subunits are
called
capsomeres
CAPSOMERES
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WHY ARE THEY NONLIVING?
• Outside of host cells,
viruses are inactive
• Lack ribosomes to make
enzymes needed for
polypeptide synthesis &
DNA replication.
• Use the host cell’s
organelles and enzymes to
reproduce
HIV
VIRUS
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EBOLA VIRUS
VIRAL SHAPES
Viruses come in a variety of shapes
Some may be helical shape like the
Ebola virus
Some may be polyhedral shapes like
the influenza virus
Others have more complex shapes like
bacteriophages
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HELICAL VIRUSES
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POLYHEDRAL VIRUSES
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USED FOR VIRUS
IDENTIFICATION
1.
2.
3.
4.
RNA or DNA Virus
Do or do NOT have an envelope
Capsid shape
HOST they infect
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SELECT A POSITION
From the perspective of the virus, is it best for a
virus to kill its host or to not kill its host?
Write your answer in your notebook .
WHICH IS BETTER?
To K i l l
Not to Kill
Watch video and try to answer questions 1-12. Listen for specific types of human cells
which help Holly to live or not.
HOLLY GETS SICK
PRE-VIDEO
Successful Virus Infection:
1. Entry – just getting into body isn’t a guarantee
2. Spread – must get to the specific area in body
3. Multiply – infect specific cell type – go lytic!
4. Damage – cause illness
What will happen to Holly?
BACTERIOPHAGE (PHAGE)
Virus which infects E.coli bacteria.
Phage uses tail fibers to attach to cell.
Only DNA is injected into cell.
Capsid remains outside cell.
Study picture to left. Notice only one
Phage completely without DNA (one
with white capsid.
Viral protein not needed inside cell
because it is the DNA that is the ]
information for making more virus.
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VIRUS LIFE CYCLES
VIRAL DISEASES
Some viruses cause disease
Smallpox, measles,
mononucleosis, influenza,
colds, warts, AIDS, Ebola.
Some viruses may cause
some cancers like leukemia
Virus-free cells are rare
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MEASLES
HOW BODY FIGHTS A VIRAL INFECTION OR
ANY PATHOGEN
Nonspecific: Doesn’t
discriminate
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•
•
•
•
•
•
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Fever
Macrophages
Nostril hairs, skin
Mucous
Natural Killer Cells
Interleukins
Antimicrobial proteins
Histamine and inflammation
Specific: Cells specifically id
the vir us
• Dendritic cell
• Lymphocytes
T cells: Helper and Killer
B cells: makes antibodies
* Both specifically target the virus
and mature in the lymph nodes
*Killer T and antibody destroy
virus
• Memory cell
Our immune system backs up our nonspecific defense system.
To the left is a macrophage using phagocytosis to
destroy bacteria. Below is a picture of tissue
damage showing macrophages destroying bacteria
at the site of tissue damage.
Illustration of tissue damage
Tissue injury; release
of chemical signals
such as histamine
Dilation and increased leakiness
of local blood vessels; migration
of phagocytes to the area
Phagocytes (macrophages and
neutrophils) consume bacteria
and cell debris; tissue heals
B cells secrete antibodies that attack
antigens ( anything foreign)
T cells attack cells infected with the
specific virus or pathogen.
REVIEW QUESTIONS
What is the difference between the lytic and lysogenic viral life cycles”
What part of the virus remains outside the host cell? Goes into host cell?
What part of the virus provides the genetic information to make more nucleic
acid, capsids, envelopes and glycoprotein receptors?
What part of the virus must be like the host cell?
What is a vaccine?
What are two ways in which you can achieve immunity from a infection?
What is the difference between active immunity and passive immunity?
Name all the types of immune cells and state their function.
How can a viral or bacterial outbreak be prevented or controlled?