Transcript Viruses & Bacteria

Viruses ,Bacteria, Fungi, &
Parasites
What are Viruses?
Flu
Viruses are tiny particles of DNA or
RNA that are coated with protein.
Sometimes they contain an
envelope made of membrane.
They can’t reproduce on their own
and they won’t survive long outside
a living cell.
Ebola
HIV
T4 Bacteriophage
The Structure Of a Virus
Viruses are composed of
a core of nucleic acid.
 The Nucleic acid core is
surrounded by a protein
coat called a capsid.
 The Nucleic core is either
made up of DNA or RNA
but never both.

1. Viruses attach to the host cell
membrane. (like a puzzle)
2. They inject their DNA
(instruction for making more
viruses) inside the cell.
3. They use the cell’s machinery to
reproduce,(make more copies)
4. They rupture (burst) out the host
cell killing it.
Some viruses can hide their
DNA or RNA inside the host
cell for many years before they
begin to kill cells!
HIV virus attacks white blood
cells called T-cells. It causes
the disease AIDS.
Smallpox,
Chickenpox, flu, and
warts are also
caused by viruses.
Adenoviruses cause the
common cold. They attack
cells in your respiratory
system.
CANNOT Kill a virus because it is not alive.
NO medicines can cure!!!
So…we get a vaccine.
Vaccination Facts 101:
1.Helps immune system fight disease
2.Contains a weakened form of a pathogen
3. Immune system make antibodies to destroy
pathogens for future exposure
4. Vaccine does not carry a live pathogen
5. Can almost eradicate (eliminate) or significantly limit
the number of cases of certain viruses
• Measles
• Mumps
• Smallpox
- Preventing Infectious Disease
Active Immunity
A person acquires active immunity when his or her
own immune system produces antibodies in
response to the presence of a pathogen.
Flu Attack! How a virus invades
your body!
Achoo!!!
Bacteria Cell
Prokaryotes




Cells that do not have a
nucleus
Exist almost every where
on earth
Grow in numbers so great
you can see them with
the unaided eye
Are placed in either the
Monera Kingdom
DRAW
ILLUSTRATION
Bacteria are different
from viruses. They
cause disease by
secreting (dumping
out) toxins that
poison cells.
Bacteria often enter the body
in food and water, or through
cuts in the skin.
Soil Bacteria
Diseases caused by Bacteria
Disease
Lyme Disease
Tetanus
Tuberculosis
Diphtheria
Strep Throat
Effect on Body
Bulls eye rash at site of tick bite. Fever and
fatigue
Muscle spasm, paralysis, death
Fatigue, weight loss, mild fever, cough, death
Sore throat, low fever, difficulty swallowing and
talking, death
Fever, sore throat, swollen glands
- Viruses, Bacteria, and Your Health
Common Bacterial Diseases
Many bacterial diseases can be cured with
antibiotics.
Bacteria and Disease
Antibiotics are substances that kill
bacteria or slow their growth.
– Misuse gives bacteria the upper hand
– Some bacteria resist the antibiotics
Movement
• Flagella ~ Tail like structure the whips
around to propel (move) the bacterium
• Cilia ~ Miniature flagella surround the cell
that help to “swim”
• Non motile ~ Sticky cilia like structures
that keep the bacterium from moving
Bacteria Reproduction
• Bacteria can reproduce at
tremendous speeds. Some
bacteria can reproduce as
often as once every 20
minutes!
• All bacteria use either asexual
or sexual reproduction.
• Types of reproduction:
1. Binary
Fission
2. Conjugation
3. Spore Formation
Cellular organism copies it’s genetic information then splits
into two identical daughter cells. Binary Fission allows
bacteria to reproduce so quickly because they are always
DOUBLES the amount of bacteria cells.
Not all bacteria are harmful! Many are BENEFICIAL!
They provide something we need. Soil bacteria
called 1.nitrogen fixers make nitrogen in the air into
fertilizer in the nitrogen cycle. 2. Decomposers
break waste back down into organic material and
carbon dioxide.
We rely on 3.
bacteria in our guts
(stomach &intestines)
to help with digestion.
We use some
bacteria to 4. produce
food like yogurts,
cheeses, wine, soy
sauce, etc.
5. Insulin Production
Graphic Organizer
Nonliving
Can be
useful
Treated with
antibiotics
Another Agent of Disease
A fungus is an unicellular or multicellular
spore producing organism classified in
the kingdom of Fungi. Most disease
causing fungi are single-celled. Its cell
contains a nucleus like plant and animal
cells
Obtaining Nutrients
• Fungi use hyphae that grow into the food
source to absorb nutrients.
– Some decomposers & recyclers for nutrients
– Some are parasites
Did you know?
• Fungi are really not that similar to plants.
• Many fungi are economically valuable.
• Many fungi are beneficial to other
organisms.
Helpful Fungi
• Fungi can be used to benefit us.
– Food – mushrooms, blue cheese, yeast to
make bread rise.
– Fight Disease – Makes antibiotics
• Penicillin
Harmful Fungus
• Fungi can also cause us harm
– Cause food spoilage and plant disease like
Dutch Elm Disease and mildew.
– Cause human diseases such as Ring
Worm, Athlete’s Foot, and Yeast Infection.
Fungi and Disease
Candida
Ringworm
Athlete’s foot
A group of yeast. Can invades many parts of
the body. Cause skin, lung and heart infections
Affects the neck, scalp, groin, or feet.
Picked up from the environment. Fungus
thrives in wet and warm areas. Hard to cure.
Type of ringworm.
Another Agent of Disease
Some diseases found in humans are
caused by parasites. These organisms live
on or in another organism and use the
organism on which it lives, as a source of
food.
Diseases caused by Parasites
Parasites do not kill their host. If they did,
the parasites would lose the benefits that
they gain from that organism.
Humans become weak and sick when
parasites use them for nourishment, like
tapeworms.
Parasite/Disease
Sleeping Sickness
How Disease is Spread
The tsetse fly transfer the organism form
another host, such as a cow
Amoebic Dysentery Parasites are acquired from contaminated water
or from food contaminated by untreated sewage
Malaria
The Anopheles mosquito transfer the organism
to the human bloodstream
Roundworm
Invades the gastrointestinal tract after its eggs
are consumed in contaminated foods
Pinworm
Tapeworm
Worm’s eggs are consumed in contaminated
food. Worms hatch and move into colon.
Worm’s eggs are eaten in contaminated food.
Eggs hatch in intestines and attaches to lining of
intestinal wall feeding on the organism.
Vectors
Vectors are living organisms
that can transmit infectious
diseases between humans or
from animals to humans.
Many of these vectors are
bloodsucking insects,
1. TICK
2. MOSQUITO
4. Teste Fly
3. FLEA