Transcript Viruses and Bacteria - Madison County Schools

Viruses and Bacteria
What is a Virus?
• A virus is a tiny, non-living particle that enters and
reproduces inside a living cell.
Characteristics
1. Viruses are not cells.
2. Do not use their own energy to grow or respond to their
environment.
3. Can not make their own food.
4. Can not produce waste.
5. Can only multiple when they are inside a living cell.
6. Need a host (like a parasite) to receive energy and
reproduce.
Virus Shape
1.Round
2.Rod
3.Threads
4.Bullets
Bacteriophage-viruses that
infect bacteria.
Structure of Viruses
Protein Coat- to provide ?
Inner core of genetic material.
Why? What does RNA carry?
Viruses multiplication
• One virus infects one cell to produce 50 new viruses. First
Generation
• How many viruses do you have after just three generations?
Each generation reproduces after 5 hours.
• Active viruses-like a photo copier, invades a cell and makes
copy after copy until cell explodes releasing newly made
viruses.
Viruses multiplication
Hidden Virus- Enters a host and places genetic material in
the DNA of a host. After a period of time, the genetic
material separates to become a “virus factory.”
Conditions that potentially increase activity:
1. Stress
2. Extreme sunlight
3. Usually found in nerve endings
Core sores…
Viruses and Gene Therapy
Gene Therapy-scientist utilize the ability of a virus to
insert genetic material into a host cell. Uses the virus as a
message carrier to deliver genetic material. Used to treat
many disorders: cystic fibrosis, cancer, inflammatory
bowel disease, Parkinson's disease, and others.
Muhammad Ali
and Michael J. Fox
Bacteria
Communication
tendrils
Anton Van Leeuwenhook
• Discovered Bacteria accidentally (water droplets) in late 1600’s
• Made microscopes as a hobby
• Looked at plaque from teeth with microscope to see tiny worm
like structures.
Bacteria Structures
Prokaryotes- genetic material found floating in cytoplasm.
Surrounded by a rigid cell wall
Has a cell membrane
Ribosomes
Many have a flagellum, a whip like structure used to aid in movement
Others can be carried by wind, water, or organisms to other locations
Three Basic Shapes
Coccus or Round
Spirillum or spiral
Bacilli or rod-like
Food and Energy
Bacteria need a source of food and a means to break it down to
release energy (respiration).
Obtaining food- Some are autotrophs ( Which means ?) using
what process? Some are heterotrophs (which means?)
Another process to obtain energy is chemiosmosis
Reproduction
Under the right conditions, right temperature, and suitable
conditions reproduce quickly, every 20 minutes.
Asexual Reproduction1. Binary Fission- split into two identical cells. One parent.
Sexual Reproduction1. Two parents combine genetic material through a process
called conjugation, a threadlike link between bacterial where
genetic material transfers.
Endospore Formation
Sometimes conditions are unfavorable: food scarce, no
water, extreme climate. This results in an endospore-a
small, rounded, thick walled, resting cell that forms inside
a bacterial cell. Contains genetic information and last for
years.
Science Explain Superstition
Tetanus is a medical condition characterized by a prolonged
contraction of skeletal muscle fibers, the primary symptoms
are caused by tetanospasmin, a neurotoxin produced by the
Gram-positive, obligate anaerobic bacterium Clostridium
tetani. As the infection progresses, muscle spasms, and
difficulty swallowing and general muscle stiffness.
Importance in Nature
1.Involved with oxygen production
2.Involved in food production
pasteurization
3.Environmental recycling
Decomposers
Nitrogen-Fixing Bacteria/Nodules (symbiotic relationship)
4.
Human health
Digestion
Vitamins
5.
Medicine production
Viruses, Bacteria, and You
Infectious disease-an illness that passes from one
organism to another.
Spread by:
1. Contact
2. Contaminated objects
3. Infected animals
4. Environment
May enter the body through breaks in the skin, inhaled,
through ears, eyes, mouth, or any other body opening.
History of Penicillin
Alexander Fleming
Treating Infectious Disease
Bacterial Disease- cured by antibiotics, which weaken the cell
wall causing bacterial cell to burst.
Problems-Antibiotic resistant, a serious problem
Viral Disease- No cure
Preventing Infectious diseaseVaccine is a substance introduced into the body to stimulate the
production of chemicals that destroy specific viruses and
bacteria.
Stay healthy- nutritious food, adequate sleep, fluids, and
exercise. Protect yourself by washing hands. Store food
properly, keep kitchen surfaces “CLEAN,” and proper cooking.
http://www.stevespanglerscience.com/science
-video/growing-bacteria