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Bacteria, Virus & Immune Response Unit
Bacteria
Prokaryote
Structure/ Functions
Basic Structures (all bacteria have)
Cell wall, cell membrane, cytoplasm, DNA (CLOSED LOOP)
No organelles
Still organization… (cytoplasm or cell membrane)
Still carries out life processes/homeostasis
Secondary Structures (specialize bacteria) *provide pictures to show differences
Endospores (Gram + has for survival needs), capsules, outer membrane
(Gram – does), plasmid, pilus, flagellum
Types of Bacteria
Shapes
Rods (bacilli), spheres (cocci), spiral (spirilli)
Why are they different?
Differences in genetic makeup.
Adaptations/ survival needs- Is this true?
Living Environment
Obligate anaerobes
Can’t survive in Oxygen
Facultative anaerobes
Can live with or without oxygen
Obligate aerobes
Can’t live without oxygen
Thermophlyes, Halophiles
Reproduction
Binary Fission
Asexual reproduction
Steps of BF
Inquiry activity: students order pictures with no prior knowledge.
Bacteria can obtain new traits/adaptations through varies methods, with
mutations being the methods. (transduction, conjugation, transformation)
Why is their reproduction so fast?
Simple reproduction
Smaller amount of DNA
To account for agents that work against them.
Fast copying of DNA turns into mistakes
They are single-celled, therefore they don’t live long lives. (HOW
LONG?) As short as 15 minutes, as long as a few days
Transmission Lab
NaOH Phenyl Phaline test tube lab (Outbreak movie)
Bacteria, Virus & Immune Response Unit
Viruses
Intracellular Obligate Parasite
Tiny non-living particles
Named for disease they cause.
Contain genetic material
Structure
Genetic material, outer protein coating, (maybe a membrane)
Viruses are specific to the host cell they invade.
Connections are specific
Marker proteins that fit together like puzzle pieces
Can only enter a few types of cells
Reproduction
Lytic (Virulent)
Host DNA destroyed
Cell does not carry out its normal life processes. It’s machinery is
hijacked by the virus.
New viruses made immediately and host cell dies
Lysogenic (Temperate)
Host DNA not destroyed, instead viral DNA becomes integrated or
inserted into the host DNA
Cell still functions normally
Cell still reproduces normally
Virus can stay undetected for a long time until conditions are right and
trigger the viral DNA to be active and convert to lytic cycle.
Is a virus living?
NO
Characteristics of Life.
Can’t reproduce by itself,
Not made of cells
They can evolve and they do contain genetic material
Mutation (good/bad)
*Movie- Outbreak
They do not need energy (don’t need food)
Don’t increase in size
Don’t get new parts in their life time
Don’t respond to their environment.
Immune Response
Why is it considered an organ system? (reflect back on levels of organization)
How does it help with homeostasis/life processes
What specialized cells are involed
Lymphatic System
Lymph is extra-cellular fluid contains water and dissolved substances from blood
Bacteria, Virus & Immune Response Unit
This fluid is circulated and filtered by things such as lymph nodes, spleen and
tonsils which contain WBCs to attack antigen.
A system that is a line of defense for your body
Maintains homeostasis by keeping body fluids at constant levels
Absorbs fats from digestive tract
Helps fight against disease
Non-Specific Defense Mechanisms
Innate immune system
NONspecific
Skin
Fist line of defense
Millions of bacteria on it at all times
Some bacteria is good for us.
Infections arise only when a particular type of bacteria meets the right
conditions, thus allowing it to flourish and multiply rapidly.
Other physical mechanisms
Sweat, tears, saliva
All contain enzymes that can break down the cell wall of bacteria
Mucus
Keeps parts from drying out. In respiratory and digestive tract
traps microbes.
Stomach gastric acids
Phagocyte (Macrophage)
Phagocytosis- engulfing of a cell by another cell
Inflammation
Redness, swelling, pain, heat
Redness- from increased blood flow to area
Swelling- from increased blood flow/fluids to area
Pain- Pressure on nerves from swelling
Heat- increase in temperature to kill pathogens
SPECIFIC IMMUNITY
Recognizing self/non-self
Specialized lymphocytes produce antibodies specific to the antigen (any
substance that is recognized as non-self)
Memory- stores agents to fight against future pathogens
Many different types of WBCs, response depends on antigen
Antibody Immunity
T cells recognize and bind to antigens.
T cells activateB cellsplasma cellsantibodies
Antibodies attack and kill antigen
Memory cells stay around and circulate to prevent future invasions of the
same antigen
Types of T cells
Helper T cells- Activate cytotoxic T cells
Bacteria, Virus & Immune Response Unit
Cytotoxic T cells- kill antigens/pathogen
Pandemic/Epidemic
Virus/Bacteria Fun Facts
H1N1
Pathogenic/ Non-pathogenic