What are these tiny particles? Pages 210 - 215 Viruses What are these tiny particles? Pages 210 - 215

1.What is a Virus? A tiny non-living particle that invades and then multiplies inside a living cell. They are NOT cells Do NOT have characteristics of organisms

2. What does a virus need in order to multiply? Viruses need a host that they can multiply within The only way viruses are like organisms is that they can multiply Host: A living thing that provides a source of energy for a virus or an organism.

3. How is a parasite like a virus? PARASITE: Organisms that live on or in a host and cause harm to it. Viruses and parasites are similar because they both have hosts that they depend on for energy. Almost all viruses destroy their host cells!!!!

Parasite Examples Parasite living inside a human HOST Parasite living on the outside of a caterpillar HOST

4. Characteristics of Living Things 1. Made of cells 2. Composed of Chemicals 3. Use Energy 4. Respond to Stimuli 5. Grow and Develop 6. Reproduce (Make more of themselves) Mrs. Carey’s Fabulous Four 1.Reproduction 2.Metabolism 3.Response 4. Growth

Characteristics of Living Things REMEMBER,THE ORGANISM MUST HAVE ALL OF THE CHARACTERISTICS TO BE CONSIDERED LIVING!

5. Viruses, Living or Non-living? NON-LIVING!!!! They do not have all the characteristics of living things!!!! They MULTIPLY, no REPRODUCE!!!!!

6. Structure Viruses come in various shapes and sizes A. Round B. Rod C. Bricks D. Thread E. Bullets

Shapes of Viruses

Structure of Viruses 7. Some of more complex, like the bacteriophage. BACTERIOPHAGE: A virus that only infects bacteria.

Bacteriophages Continued 8. Bacteriophage literally means “ bacteria eater”.

Capsid: Protein shell of a virus

Virus Similarities 9. Even though all viruses look different from each other, they all have similar structure. 10. Virsuses have two basic parts: A. Protein Coat: Protects the virus B. Inner Core: Made of genetic material * A virus’s genetic material contains the instructions for making more viruses. *

Virus Structure

11. Protein Coat Each virus contains a unique protein coat. 12. Like keys, virus’s proteins only fit into certain “locks” or proteins. Only specific viruses fit with specific host cells.

Protein Coat Example: Most cold viruses only affect cells in the nose and throat of humans.

How Viruses Multiply? 13. Once inside a cell, a virus’s genetic material takes over most of the cell’s functions. Genetic material = DNA The genetic materials instruct the cell to produce virus’s proteins and genetic material.

How Viruses Multiply? 15. Viruses cannot multiply without a HOST! 16. Active virus enters cells and immediately being to multiply. Example: Like a copy machine left in the “on” position.

Lytic Cycle

Lytic Cycle – ACTIVE Viruses Step #1 - Attachment: Virus attaches to the surface of a host cell Step #2 - Injection: Virus injects genetic material into host cell Step #3 - Production: Virus’s genetic material take over host cell and starts to produce proteins and genetic material Step #4 - Assembly: Proteins and genetic material assemble new viruses Step #5 - Release: Host cell bursts and releases new viruses

“Hidden Viruses” 18. Hidden viruses do not immediately become active. Instead the “hide” for a while.

Lysogenic – “Hidden” Viruses” Step #1 - Attachment: Virus attaches to the surface of a host cell Step #2 - Injection: Virus injects genetic material into host cell Step #3 – Absorb/Incorporate: Virus’s genetic material becomes part of the host cells. Step #4 – Separation: After some time, virus’s genetic material removes itself and becomes ACTIVE! Step #5 – Production & Assembly: Cell produces new viruses Step #6 - Release: Host cell bursts and releases new viruses

Lysogenic Cycle “Hidden Viruses” Under certain conditions, the virus is activated! Can stay in inactive state for years! Example: Cold Sore – Virus remains hidden for years or months until it is activated. Then the result is a red and swollen area near the mouth. VIRUSES MULTIPLY NOT REPRODUCE!!

Viruses and Diseases 20. Diseases can be spread in a variety of ways: A. Direct contact with contaminated objects B. Bites from infected animals (rabies) C. Air born (Tiny droplets of moisture) D. Contact with body fluid (blood)

Viruses and Diseases 21. There are currently no cures for viral diseases. 22. Over-the-counter medications simply relieve the symptoms.

Virus Treatment 23. The best treatment resting, drinking plenty of fluids, and eating a well balanced meals. Staying away from other potential ways that diseases can spread. Follow the food pyramid Getting 8 full hours of sleep

Preventaion 24. One way to prevent getting sick is a vaccine. 25. Vaccine: A substance used in a vaccination that consists of a weakened or killed pathogen that can trigger the immune system into action. By receiving a small portion of the virus, your body will learn how to fight it off. If your body comes in contact that virus again, it should know how to fight it off.

Prevention and Health 26. Another way to prevent disease is to keep your body healthy. 27. You can keep your body healthy by: Working out Eating healthy Getting plenty of sleep

Vaccines 28. Why don’t vaccines cause diseases themselves? They are a smaller portion, so a normal body can fight off and not get infected. Dead portion of a pathogen so can no longer multiply.

What’s next? What are Bacteria?

Bacteria!

The Bacteria Cell 1. Bacteria are: Prokaryotes (NO nucleus) Single-celled 2. Discovered by accident by Leeuwenhoek (first person to look at living things under the microscope)

3. Prokaryote or Eukaryote Prokaryote: Lacks a nucleus Eukaryote: Had a nucleus Bacteria do NOT have a nucleus so they are PROKARYOTES!

4. Parts of a Bacterial Cell Exterior View 1. Flagellum – Used for movement Interior View 2. Ribosomes – Make proteins 3. Cell Wall – Used for Structure 4. Cell Membrane 5. Cytoplasm 6. Genetic Material – DNA

4. Parts of a Bacterial Cell

Bacteria Movement 5. Some bacteria have a flagellum, which is a long, whip-like structure that can help a cell move. 6. Bacterial cells without a flagella cannot move on their own.

Bacteria Movement 7. Ways that bacteria can be carried from one place to the next: A. Air B. Water currents C. Other objects

Bacteria Size 8. Bacteria vary greatly in size. A. Size of the period at the end of a sentence. B. One millionth of a meter

Bacteria Size

11. Bacteria Shapes Spiral Rod/Pill Round

Cocci Found in pond scum

Bacilli Found in Yogurt

Spirilla Found in Hot Springs

Obtaining Food and Energy 12. Bacteria must have a source of food and a way of breaking down the food to release its energy. 13. Some bacteria are autotrophs, which means they can make their own food. 14. Autotrophs can make their food in one of two ways: Some capture sunlight (like plants) Energy from chemical substances

Obtaining Food and Energy 15. Heterotroph: Organisms that do not have the ability to make their own food Must consume energy! (Eat Food!) 16. Heterotrophic bacteria get food by: Consuming milk and meat to decaying leaves

Obtaining Food and Energy 17. Bacteria need a constant supply of energy! 18. Bacteria get this energy by: Breaking down food in process of respiration Most bacteria need oxygen to break down food A few bacteria will die in presence of bacteria

Obtaining Food and Energy Aerobes: Need oxygen to break down food Anaerobes: Do NOT need oxygen to break down food. These bacteria will die if oxygen is present

Reproduction 19. Bacteria will reproduce frequently when: Plenty of food Right temperature Other suitable conditions 20. Under the ideal conditions, bacteria can reproduce as often as every 20 minutes! (Doubling their population size!)

Asexual Reproduction 21. Asexual Reproduction: A reproductive process in which one cell divides to form two identical cells. 22. Binary Fission is a form of asexual reproduction. 23. During binary fission, a cell duplicates its genetic material, and then divides into two separate cells.

Sexual Reproduction 24. Some bacteria can also reproduce sexually. 25. Sexual Reproduction: Reproductive process where two parents combine their genetic material to produce a new organism, different from both parents. 26. Bacteria use a form of sexual reproduction called conjugation.

Conjugation

* CONJUGATION DOES NOT INCREASE THE NUMBER OF BACTERIA!* 27. During conjugation, one bacterium transfer genetic material to another using a thread like bridge. * CONJUGATION DOES NOT INCREASE THE NUMBER OF BACTERIA!*

Endospore Formation 28. If conditions are unfavorable for bacterial growth, bacteria can form an endospore. 29. An endospore is a thick, rounded, thick- walled resting cell that forms inside a bacterial cell. 30. Endospore resists against: Freezing Heating Drying

31. Endospores are so light they can be carried by wind. Endospore Formation 31. Endospores are so light they can be carried by wind.