Bacteria and Viruses!
Vocabulary—Yes!!
1.
2.
3.
4.
5.
6.
7.
Prokaryote
Bacilli
Cocci
Spirilla
Streptococci
Staphlococci
Gram negative
Bacteria
8. Gram positive
bacteria
17. Capsid
9. Capsule
18. Retrovirus
10. Pili
19. Bacteriophages
11. Pathology
20. Lytic cycle
12. Exotoxins
21. Lysogenic cycle
13. Endotoxins
22. Vector
14. Antibiotic resistance23. Inactivated virus
15. Zoonosis
24. Attenuated virus
16. Virus
Prokaryotes—Quick Review!
•Prokaryotes are single celled organisms that do
NOT have a membrane bound nucleus.
•Prokaryotes are the most numerous organisms
on Earth and live almost everywhere
•Most prokaryotes are BACTERIA
•Some are ARCHAEA-mostly ancient organisms
that live in extreme environments
Classifying Bacteria
• Bacteria are
identified by 3
characteristics:
Shapes
• 3 shapes: rod, spherical, spiral
Cell Walls
• Thick walls, thin walls
Movement
• No movement, flagella, lash/snake/spiral
forward, glide on secreted material
Bacteria—3 Basic Shapes
Bacilli
Rod-Shaped
Cocci
Spirilla
Sphere Shaped
Spiral Shaped
Gram Stain
• Bacteria can be classified into 2 categories based on the structure of
their cell walls using GRAM STAIN.
• GRAM NEGATIVE BACTERIA take up the red of the gram stain process,
turning reddish pink under a microscope
• GRAM POSITIVE BACTERIA take up the purple dye and look purple
under a microscope.
Bacteria—Structure and Function
• Cell wall, cell membrane, cytoplasm
• DNA, floating
• Capsule—outer covering made of polysaccharides
• Pili—short, hair-like proteins on the surface of the
bacteria, helps bacteria attach to surfaces and cells
• Flagella-tail like feature to allow movement towards
food or away from danger
Bacteria and Health (note: many bacteria are
good for us!)
• PATHOLOGY is the scientific study of disease
• EXOTOXINS are toxic substances that bacteria secrete into
their environment (tetanus)
• ENDOTOXINS are toxic substances that are part of the outer
membrane of bacteria and are not released until the cell dies
(E.Coli)
• ANTIBIOTICS are chemicals that inhibit the growth or kill
bacteria
• ANTIBIOTIC RESISTANCE is the evolution of populations of
bacteria to resist (and not die) antibiotics.
Importance of Bacteria!
• Bacteria are VITAL to the living world
• Some are producers
• Some are decomposers
• Others have human uses (cleaning up oil, medicines,
human health)
INTERRUPTION—You’ve been exposed…
Bacterial
Diseases
Lyme Disease
Staph Infection
Flesh
Eating
Disease
Bacteria in Review: Crash Course!
POGIL
Warning! Bacterial Infection is Spreading…
Do You
Have
It?????
Honors Culturing Bacteria Lab—Day 1
• P.480-481
• Read Part A and Part B
• Decide what 3 places you think will have lots of
bacteria
• Set up your petri dish
• Make a hypothesis
• Collect Bacteria
• Place Petri dishes in designated locations
Culturing Bacteria Lab—1 week later
• Lab Write Up:
1) Question (Which location will have the most bacteria
present?)
2) Hypothesis
3) Materials List
4) Procedure
5) Data—Draw out your petri dish
6) Discussion/Results/Conclusions—answer questions
1-8 on page 481 “Analysis and Conclusions” (you do not
need to write the question, but re-state the question in your
answer)
Presentation of Data
• Your group will create a poster to illustrate your findings
• Posters must include:
•
•
•
•
•
•
Locations of your swabs
Your hypothesis
Results (in writing and with an illustration of your petri dish)
Conclusions
Discussion of measures to be taken to improve situation
Recommendations for further experiments
• Groups will walk around and view the other posters and peer grade
Viruses!
A VIRUS is a nonliving particle made up or nucleic acid and a
protein coat and cause disease.
Viruses are VERY small
Viruses are NOT living because:
• They lack cytoplasm
• They lack organelles
• No metabolism or homeostasis
• Can only reproduce while in a host cell
VIRAL REPLICATION
• Outside the host cell, a virus is a lifeless particle with
no control over its movements
• It is spread by air, in water, in food, or body fluids
• A virus recognizes a host cell and then attaches to it
and the infection begins
• Once in a host cell the viruses DNA can make mRNA or
the viruses RNA serves as mRNA and they begin to
replicate more viruses
Viral Infection
• Once a virus is inside a host cell 2 different processes may occur—
Lytic Infection or Lysogenic Infection
Lytic Infection
• Virus enters the cell, makes copies of itself,
causes the cell to burst.
• When the cell bursts all of the copies are
released and can infect other cells
Lysogenic Infection
• Virus enters host cell, integrates its DNA into the
DNA of the host cell, and the viral DNA replicates
along with the host cell DNA.
• The Viral DNA can remain in the cell for
generations
• Eventually the viral DNA leaves and becomes a
lytic infection
How a Virus Works Video Clip
Viral Diseases
• Since viruses are lifeless they must be spread by
other agents…humans, animals, insects, etc.
• Common Viral Diseases:
• Chicken pox, shingles, viral hepatitis, HIV,
SARS, Avian Flu, West Nile, Influenza, Ebola
Chicken Pox and Shingles
Virus Treatment
• Vaccinations and Vector Control
• A VACCINE is a solution that contains a harmless
version of the virus (inactive or weakened).
• VECTOR CONTROL is a the control of animal vectors
such as mosquito and rabies control
• Drugs/Medications do not work well on viruses
because it is hard to find something that can block the
virus but not harm the host cell.
Vaccinations—good or bad??
Complete your 4 post-its while/after watching the video clip.
Clarify
Content
• What words or ideas were
confusing? Or maybe you
didn’t know them?
• Summarize the content in the
video
Connections
Conclusions
• Make at least 2 connections
from the video to something
you have learned in biology or
something in your life
• Does the information in the
video change your thinking
about vaccines? What is your
opinion about vaccines?
Comparing Bacteria and Viruses
Comparing Bacteria and Viruses #2
• Watch the clips
• Create a t-chart to list characteristics of both
bacteria and viruses
• After the video clips, add to the t-chart
• Write an 8 sentence or longer paragraph to
compare and contrast bacteria and viruses.
Measles and DisneyLand—A Case Study