Organization of Living Things& Viruses

Living Things

• Multi-cellular: having more than one cell• Benefits: larger size, longer life, and cells can be

specialized (have a specific job)• Tissue: made of many cells– 4 main types in animal organisms - nerve, muscle,

connective (ligaments), and protective• Organ: collections of 2 or more tissues that

carry out certain functions in the body• Organ System: group of organs (examples-

digestive system, circulatory system, etc.)

Pre- Quiz: Viruses

1. What is a virus?

2. Think of 3-4 illnesses that are caused by viruses.

3. How can viruses be treated?

Viruses• Virus: a strand of hereditary material

How do Viruses Multiply?

• Viruses must be inside a host cell in order to multiply.

• Once a virus is in a cell it can be active or latent (which means it waits until later to become active/in hiding)

• The process of multiplying destroys the host cell.

Fighting Viruses

• Write your answers and then compare with your neighbor– Have you ever had a vaccine?– Do you know what illnesses you’ve had a vaccine

for?– How old were you the last time you got a

vaccination?

Fighting Viruses

• Edward Jenner invented the 1st vaccine in 1796– He invented the vaccine for smallpox

• Vaccines- made from weakened virus particles that can’t cause disease anymore– There are vaccines for many diseases including

measles, mumps, smallpox, chicken pox, polio, and rabies

Fighting Viruses

• There are very few anti- viral medications that work– This is why during outbreaks of viral diseases, like

H1N1, make headlines

• The best way to prevent viral diseases is to avoid them if possible, use good hygiene, and get vaccinations that are available

• Show virus film

Discussion Questions

• Think about these questions for a minute:– How does your body fight viruses?– Who invented the polio vaccine?– How can new viruses emerge?– What viral disease affects 1% of people between

15 and 49 and is especially prevalent in Africa?– What is one way new diseases are being

monitored and controlled?

Wrap- up: What do you know now?

1. What is a virus?

2. Think of 3-4 illnesses that are caused by viruses.

3. How can viruses be treated?

• 1. Explain why a doctor may not give you any medication if you have a viral disease.

• 2. Make a list of reasons that a latent virus may become active.

• 3. What are the 2 things found in every cell?• 4. What organelle is called the “powerhouse”

of a cell?

Part 2: Cell Processes

Demonstration• There will be three bowls:

– Two carrots will be placed in a solution of salt water for the rest of class

– Two carrots in plain water– Two will not be in water at all

• One your note sheet, make observations about what happened to the carrots in each bowl

• Using your observations, explain what happened to each pair of carrots.

• Passive Transport: The cell doesn't use energy to move something through the cell membrane. There are 3 kinds- – Diffusion: where molecules move from area of

higher concentration to an area of lower concentration (ex. Salt water)

– Osmosis: The diffusion of water through the cell membrane

– Facilitated Diffusion: The protein in the cell membrane help larger molecules (like glucose) through

• Active Transport: energy is required to move things through the cell membrane– Transport proteins bind with particles and cellular

energy is used to move it through the membrane. Once the particle is through, the protein releases it.

• Endocytosis: The taking in of substances into the cell by part of the membrane wrapping around it (for larger things). Some cells get food this way.

• Exocytosis: The contents of a vesicle being released by a cell (opposite of endocytosis).– EXAMPLE: Cells in your stomach release digestive

juices this way

Amoeba and endocytosis

• Equilibrium: when the amount of things leaving the cell equals what is coming in. When a cell can maintain it on it's own, it is call homeostasis.

Viewing Cells

• Cells could not be studied until Van Leeuwenhoek inventing the microscope in the 1600's

• His microscope magnified things 270x, but the image was not always clear

Microscopes Today• There are 3 main types of microscopes:

– Simple- like a magnifying glass (one lens)– Compound- 2 sets of lenses (eyepiece lens and

objective lens). • Multiply the magnification of each to get the total

magnification (example if the eyepiece lens is 10x and the objective lens is 43x, then the object is magnified 430x).

– Electron Microscope- Many kinds exist, but used for very small things such as viruses.

What are you looking at?

• I will be showing a series of pictures that show objects under a microscope.

• Your job is to make a guess to what the object is:– Is it a cell? If yes, what kind (prokaryotic or

eukaryotic; plant, animal or bacteria- or possibly a virus)

– What parts (organelles) can you clearly see?

1.

2.

3.

4.

5.

6.

1. Plant: Leaf

2. Animal Cell: Nerve

3. Plant Cell: Root

4. Animal Cell: Heart (Muscle)

5. Prokaryotic: Bacteria

6. Virus: From an electron microscope

Wrap- Up

• Look at the diagram on pg 509 of your book• Pick either diffusion/ osmosis, facilitated

diffusion, active transport, or endocytosis/exocytosis and explain in your own words what it is (how it works), how large/what kinds of particles move that way, and then give an example of something that moves that way.

Bellwork 4/15/10

• 1. Compare and Contrast the processes of osmosis and diffusion.

• 2. Why do you think fruits and vegetables are sprayed with water at the grocery store?

• 3. Why did the carrot left in the salt water become spongey versus the one left in fresh water?

Bellwork 4/16/101. Complete a notebook check

2. Compare a simple and a compound microscope.

3. Why would you think it would be better to look at living cells than dead cells under a microscope?

4. Look at the picture. What type of cell is this and what organelles can you see?

Part 3: Energy for Life

Preview Questions

1. List the differences between producers and consumers

2. Explain how the processes of photosynthesis and respiration store and release energy.

3.Describe how cells get energy from glucose through fermentation.

Trapping and Using Energy

• Chemical reactions occur in cells. These chemical reactions release the energy needed for a cell to work.

• Metabolism: the total of all chemical reactions in an organism

• The chemical reactions of metabolism need enzymes.

Trapping and Using Energy

• Enzymes in cells cause a change, but the enzyme is not changed and can be used again.

• Enzymes cause molecules to join.• Each chemical reaction in a cell requires a

specific enzyme.• Enzymes are used in both photosynthesis

and respiration

Trapping and Using Energy

Photosynthesis• Plants convert light energy into chemical

energy in their chloroplasts.• Do you remember the chemical formula for

photsynthesis?– 6CO2 + 6H20+ sunlight C6H12O6 + 6O2

– Chloroplasts capture the light energy– Some of the energy is stored in the bonds of

the sugar molecule– Sugar is used for growth and reproduction.

Excess is stored as starch.

Respiration

• Respiration is the chemical reactions used to break down food

• It is basically the opposite of photosynthesis– 6O2 + C6H1206 6H20 + 6C02

• The energy released is used in your muscles as well turning into thermal energy (which is why you get warm when you move a lot)

Respiration

• Carbohydrates are the easiest molecules for your body to break down

• The breaking down of glucose (a type of carb) releases energy for your body

• Respiration occurs in every living thing

Fermentation

• The process of breaking down sugar molecules in oxygen lacking cells or single celled organisms

• Releases less energy than respiration

• Depending on the cell, the sugar turns into C02

& alcohol (ex. In the baking of bread) or into lactic acid (in your body)

Review Questions

1. List the differences between producers and consumers

2. Explain how the processes of photosynthesis and respiration store and release energy.

3. Describe how cells get energy from glucose through fermentation.