Monday Warm Up 5/23Use your video questions from Friday to answer

1. What killed more people than World War I?

2. How does a virus reproduce?3. Why should countries immediately

report a spreading disease?

Monday Agenda

• Today– Objectives: SWBAT differentiate between

bacteria and viruses– Finish Swine Flu Video and Questions– Notes/ Comparison Chart– Epidemic Reading and Questions– Reading Guide 31.1

Swine Flu Video

Are Viruses Alive?

• Viruses need a host cell in order to reproduce.

• They also cannot grow or maintain homeostasis

• That means they are NOT living.

Viruses• Size: 20- 400 nano meters (nm = 1 billionth of a meter)• Structure

– Contain either DNA or RNA– Surrounded by a protein coat called a capsid

Video• http://

www.npr.org/blogs/krulwich/2009/10/23/114075029/flu-attack-how-a-virus-invades-your-body

• http://player.discoveryeducation.com/index.cfm?guidAssetId=8819B0AE-8366-4E0F-938F-1B9FC9D57EA7&blnFromSearch=1&productcode=US

Life Cycle of a Virus• Infection: virus attaches to cell and injects

DNA or RNA

• Replication: DNA of viruses is copied by the cell

• Assembly: newly made viruses are put together

• Lysis: when viruses burst through the cell, causing cell death

Virus Cycle

Diseases caused by viruses

-Many diseases are caused by viruses including: Common cold, flu, small pox, warts and HIV.

Type of Infection• Viruses affect the

whole body once someone is sick, which is called a systemic infection.

Treatment?

• You can treat the symptoms, but it’s up to the immune system to fight a viral infection.

• Treatment includes– Painkillers, or medicine to treat symptoms– Drinking plenty of water– Vaccines (only prevent future infections)

Bacteria• Bacteria are small, one-celled

prokaryotes.

• Bacteria reproduce asexually through mitosis and binary fission.

Structure of Bacteria• All bacteria have a cell wall

and/or cell membrane, cytoplasm, and DNA

• Some bacteria are surrounded by a capsule which keeps them from being eaten by white blood cells.

• Size: ~ 1000 nm

Bacteria

Benefits of Bacteria• Most bacteria is beneficial!!!!• Uses of bacteria

– Making dairy products (yogurt, sour cream, cheese, milk)

– Probiotics contain bacteria and are used for digestive health and medicinal purposes

– Some bacteria decompose waste– Bacteria is used to consume oil in the ocean

Bad Bacteria cause Diseases

• Some bacteria cause diseases such as Strep Throat, pneumonia, tetanus, spinal meningitis.

• Only bacteria that have capsules are infectious (can cause disease).

Type of Infection• When bacteria cause an

infection, it is localized or only affects a certain area of the body.

Treatment• Bacterial infections are

typically treated with antibiotics that will typically kill the bad bacteria.

How can you get infected?

Airborne Contaminated food or water

Contaminated blood products

How can you get infected?

Sexual contactInfected Animals or Vectors such as Mosquitoes

Comparison Chart

Epidemic Reading and Questions

Tuesday Warm Up 5/241. What are some benefits of bacteria?2. What are at least two differences

between bacteria and viruses?3. What are at least 2 ways to prevent a

disease from spreading?

Tuesday Agenda

• Today– Objective: Differentiate between

nonspecific and specific defenses.– Examine different parts of the immune

system and the roles they play– Introduce Final Project– Textbook Activity– Reading Guides

Final Weeks• Library

– 3rd Period: Tues. 5/31 and Wed. 6/1– 4th Period: Fri. 5/27 and Tues. 5/31

• Next Week– Gather information and work on Project (Disease

Brochure)• Last Week

– Gallery Walk Presentations– Dissection (Hopefully!)

• Have to be passing and turned in BOTH projects

Textbook Activity

Whooping Cough

Write down the following questions and answer them after watching the video.

1. What makes whooping cough different from a regular cough/cold?

2. Why does it affect infants more?

3. What are two things adults can do to prevent spreading whooping cough?

Reading Guides

Exit Ticket

1. What is your body’s first line of defense?

2. If you have already been exposed to a virus, you will not get sick from it a second time. What type of immunity is this?

• The body’s earliest lines of defense against any and all pathogens make up your nonspecific, innate immunity.

Innate Immunity

• Intact skin is a formidable physical barrier to the entrance of

microorganisms.

Skin and body secretions

• In addition to the skin, pathogens also

encounter your body’s secretions of mucus, oil, sweat, tears, and saliva

• Because mucus is slightly viscous (thick), it also traps many

microorganisms and other foreign substances that enter the respiratory and digestive tracts.

Skin and body secretions

• Mucus is continually swallowed and passed to the stomach, where acidic gastric juice destroys most bacteria and their toxins.

• Sweat, tears, and saliva all contain the enzyme lysozyme, which is

capable of breaking down the cell walls of some bacteria.

Skin and body secretions

• If a pathogen manages to get past the skin and body secretions, your body has several other nonspecific defense mechanisms that can destroy the invader and restore homeostasis.

Inflammation of body tissues

• If bacteria or other pathogens enter and damage body tissues, inflammation (ihn fluh MAY shun) results.

Inflammation of body tissues

• Inflammation is characterized by four symptoms—redness, swelling, pain, and heat.

• Inflammation begins when damaged tissued

cells called mast cells, and white blood cells called basophils release histamine (HIHS tuh meen).

Inflammation of body tissuesHistamine released—blood vessels dilate Injury

• This increase in tissue fluid causes swelling and pain, and may also cause a local temperature increase.

Inflammation of body tissues

• Inflammation can occur as a reaction to other types of injury as well as infections.

• When a pathogen invades your body, it encounters your immune system.

What causes the symptoms of a disease?

• If the pathogen overcomes the defenses of your immune system, it can metabolize and multiply, causing damage to the tissues it has invaded, and even killing host cells.

• Active acquired immunity develops when your body is directly exposed to antigens and produces antibodies in response to those antigens.

Passive and Active Immunity

• Natural passive immunity develops when

antibodies are transferred from a

mother to her unborn baby through the placenta or to a newborn infant through

the mother’s milk.

Passive Immunity

Thursday Warm-up1. Explain in complete sentences how fighting

crime is similar to our immune system fighting diseases. You should have at least 3 quality sentences in your response.

2. What could make the immune system weaker?

Thursday Agenda

• Today– Objective: SWBAT Describe why a person

with an immunodeficiency cannot fight off common infections

– Pass out Progress Reports– Pre-Test Questionnaire– Notes– Video on spread of HIV and AIDS

KEY CONCEPTWhen the immune system is weakened, the body cannot fight off disease.

Leukemia is characterized by abnormal white blood cells.

– characterized by immature white blood cells – causes weakened immune system

• Leukemia is cancer of the bone marrow.

• Leukemia leads to opportunistic infections.– People get sick easily because white blood cells cannot

fight infections– if immune system were healthy, would fight these

infections

Examples

• Pneumonia• Tuberculosis• Bronchitis• Toxoplasmosis• Chronic ulcers

HIV targets the immune system.• The human immunodeficiency

virus (HIV) is a retrovirus. – attacks and weakens the

immune system– is transmitted by mixing infected

blood with a bodily fluid

• HIV infection leads to AIDS.

HIV

T cell deadT cell

antibody

activatedB cell

– HIV reproduces in and destroys T cells.– The body cannot replace T cells fast enough.– T cells cannot help the immune system fight infections.

• In 1981, an unusual cluster of cases of a rare pneumonia caused by a protozoan appeared in the San Francisco area.

The beginning of AIDS

• By 1983, the pathogen causing this immune system disease had been identified as a retrovirus, now known as Human Immunodeficiency (ih myew noh dih FIH shun see) Virus, or HIV.

AIDS and the Immune System

• HIV kills helper T cells and leads to the disorder known as Acquired Immune

Deficiency Syndrome, or AIDS.

How is HIV Transmitted? • There are 5 ways that HIV can be transmitted

from one person to another.

Transmission of HIV 1. Blood

2. Semen3. Vaginal secretions4. Intravenous & tattoo needles5. Mother to Child

- pregnancy- birth- breast feeding

What substances carry the virus?

* Transmission will only occur if HIV concentration high enough

Amniotic fluid Blood * Breast milk * Menstrual blood Saliva

Spinal fluid Semen * Tears Urine Vaginal secretions *

• The HIV virus is basically two copies

of RNA wrapped in proteins, then further wrapped in a lipid coat.

The AIDS virus

Proteins

Lipid coatRNA

• Once the outer proteins attach to a T cell, the virus can

penetrate the cell, where it may remain

inactive for months.

Proteins

Lipid coatRNA

The AIDS virus

• HIV contains the enzyme reverse transcriptase, which allows the virus to use its RNA to make viral DNA in the host cell.

AIDS and the Immune System

How do we test for HIV/AIDS?• Individuals that have been exposed to HIV

will produce specific antibodies against the virus

• Detecting the antibodies is the most common way to test for HIV– If antibodies are present, the person is HIV

positive

• The first symptoms of AIDS may not appear for eight to ten years after initial HIV infection.

Symptoms

• During this time, the virus reproduces and infects an increasing number of T cells.

• Infected persons may eventually develop AIDS.

• During the early stages of the disease, symptoms may include swollen lymph nodes, a loss of appetite and weight, fever,

rashes, night sweats, and fatigue.

• In most cases, it’s other infectious diseases or certain forms of cancer that cause death.

Symptoms

Video on AIDS• What are some poor ways that the country

dealt with HIV in the past?

• How has the culture of the people impacted the spread of HIV?

• How have businesses responded to the HIV epidemic?

Friday Warm Up

1. What are 3 ways to tackle the HIV/AIDS epidemic?

2. Why does Leukemia lead to a weakened immune system?

3. What disease did you pick for you brochure?

4. What do you already know about the disease?

Friday Agenda• 3rd Period

– Pass out Progress Reports– Finish watching AIDS videos– Complete AIDS Power Notes– Complete Healthy Immune System Sheet– Make-up work?– Tell me what disease you have picked for your

brochure• Monday- No School!!! • Tuesday

– Periods 3 & 4 library after attendance

Friday Agenda• 4th Period

– Pass out Progress Reports– Library for the day– Decide on a disease and have the “General

Description of the disease” section done• Monday- No School!!! • Tuesday

– Periods 3 & 4 library after attendance

Video on AIDS• What are some poor ways that the country

dealt with HIV in the past?

• How has the culture of the people impacted the spread of HIV?

• How have businesses responded to the HIV epidemic?