Cell Structure and function:

Animal cells have a thin, flexible outer layer called a cell membrane.

Plants cells have 3 things that animal cells do not: chloroplasts, cell walls, and large central vacuoles.

Prokaryotic cells do NOT have a nucleus or any membrane-bound organelles. They only have DNA, cytoplasm, a cell wall, and ribosomes.

Ribosomes are the cell parts that use the instructions from the nucleus to make proteins.

Cell membranes can only allow smaller molecules to pass through by diffusion. For large molecules to pass through, active transport must be used, like exocytosis and endocytosis.

Among other things, enzymes are useful for the body’s metabolic processes by breaking down large molecules into smaller molecules. They are involved in many cell processes, acting as a catalyst.

Infectious Diseases:

Bacteria and viruses are not the same thing! They are two very different things. They do not turn into each other. Bacteria are bacteria. Viruses are viruses.

PATHOGENS- Infectious diseases are caused by pathogens. Bacteria that cause disease are called pathogens.  Pathogens can also be other microorganisms or viruses that cause illness.

Infectious disease can be transmitted by physical contact, contaminated water and food, or by animals.

Viruses cause infection by entering the body cells and making the cells reproduce the virus. Viruses CANNOT reproduce independently (on their own).

Vaccines help a person by helping their immune systems make memory cells so that they can produce antibodies if they ever see the real thing. The memory cells provide resistance to that pathogen.

If a person receives a vaccine for a virus, then they are better able to produce antibodies to fight that virus later, if they see the real thing.

Antibiotics fight infections by killing bacteria. They can ONLY kill bacteria.

Genes and DNA:

A gene is a unit of DNA that carries information for making a protein. Genes contain information for assembling (or making) proteins.

Not all of our proteins are coded for in our DNA. Some, we must ingest.

Transcription:

Transcriptionà DNA message is copied to mRNA and taken out of the nucleus. mRNA is made.

DNA is located in the nucleus of the cell. It does not leave the nucleus. mRNA is made during transcription and mRNA takes the genetic code to the ribosomes.

Translation:

Translationà at the ribosome, the mRNA is used build proteins, also using rRNA and tRNA.

Ribosomes are the cell parts that use the instructions from the nucleus to make proteins, so translation takes place on the ribosomes.

During translation, the cell will use the message from the mRNA to make proteins. (Proteins are produced during translation.)

Messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA) are all used during the process of translation for the production of proteins.

Genetic engineering:

Researchers can use the sequence of the DNA in order to alter it to make new materials.

Transgenic organism are ones in which they have had DNA from another organisms placed into them.

Among the advantages of transgenic plants are that they can increase resistance of the plant to disease, increase crop yield, increase drought resistance, more nutritious, more delicious.

The advantage of using genetically engineered bacteria to produce human proteins is they can be used to mass produce pure human proteins to be used for medical treatments. (example, insulin for diabetics)

The Genetically Modified Foods Controversy (Concerns about impacts on human health and the environment)

most of the info in the table above came from the following web page:

http://www.ornl.gov/sci/techresources/Human_Genome/elsi/gmfood.shtml

Experimental Design:

Independent variable- something that is purposefully changed between treatments in an experiment. It is what you want so test to see how it affects something else. (in Enzymes lab, the IV was enzyme treatment)

Dependent variable- something that is affected by the independent variable. What you usually want to measure or observe as the end result of your experiment. (in Enzymes lab, it was the amount of juice made)

I. Infectious diseases (pp. 677-678)

A. Germ theory of disease (p. 677)- Infectious disease is caused by pathogens that can spread the disease from one organism to another organism

1. pathogens (p. 676)- disease-causing organisms or viruses

2. Include certain bacteria, protozoans, fungi, worms, and viruses

            B. Transmission of infectious diseases (p. 677)

                        1. Airborne pathogens can be inhaled

                        2. Physical contact can transfer some pathogens (especially if mucous membranes are contacted)

                        3. Contaminated food or water

                        4. Sexual contact

                        5. Bodily fluid exchange

                        6. Animal agent (example- Lyme disease and deer ticks)

II. Bacterial Structure

            A. Bacteria are prokaryotic cells (p. 361)

                        1. They have no nucleus        

                        2. They have no membrane-bound organelles

                        3. They are usually surrounded by cell walls made of peptidoglycan

                        4. They do have nucleic acids (DNA or RNA)

            B. Bacterial cell sketch: (p. 361)

            D. Bacterial Reproduction (p. 363-364)

                        1. Binary fission

                        2. Cells divide to make exact copies of themselves

II. How bacteria cause illness (p. 369)

            A. Directly destroying cells and tissues

            B. Producing toxic secretions

            C. Toxic cell wall components

III. Viruses infect cells by inserting genes (372-375)

            A. Viruses are not cells

            B. Virus structure and Reproduction (p. 372)

                        1. Short piece of DNA or RNA surrounded by a protein coat

                        2. Does not have its own machinery, so takes over that of other cells

                        3. Disease-causing virus uses equipment of host cell to reproduce

                                    a) Lytic Cycle- virus injects DNA or RNA into host cell, host cell makes more viruses, and host cell bursts and is destroyed

                                    b) Lysogenic Cycle (p. 372)- virus injects DNA or RNA into host cell, host cell takes in viral DNA into its DNA, each time the cell divides the new cells have copies of the viral DNA or RNA, cell lives (for the time being…)

                        4. some viral diseases include: herpes, AIDS, polio, cold, measles, mumps

            C. Defense Against Viral Diseases (p. 375)

                        1. Good hygiene

                        2. Immune system

                        3. Vaccines

                                    a. deactivated varieties of viruses or small pieces of pathogens

                                    b. stimulate immune system to defend against the real thing

                                    c. exposure to the vaccine makes the body better able to produce antibodies against the disease or pathogen in the future

                        4. Some viruses do not have vaccines

                                    a. Mutate rapidly, so the strains not recognized by immune system

                                    b. example- common cold and HIV

                        5. A few drugs have been developed to combat viruses

                                    a. These can interfere with production of viral structures

                                    b. Or they interfere with viral enzyme activity

1. Bacteria are all around. Are they always harmful? (p. 369, intro)

__No. Many are helpful or harmless to us.______________________

____________________________________________________________________________________

2. Define pathogen (p. 369):

__A pathogen is a disease-causing organism or virus.________

____________________________________________________________________________________

3. Why are most people usually healthy? (p. 369)

____Our body has structural and chemical defenses against disease.________________________

____________________________________________________________________________________

4. Bacteria cause illness in two ways (p. 369):

            1)_Bacteria can directly invade tissues and destroy cells (example: Tuberculosis).________

                ____________________________________________________________________________

            2)_Bacteria and can produce bacterial poisons._(example: botulism)____
                ____________________________________________________________________________

5. What are the two types of bacterial poisons? (p. 369)

            1)_Toxic proteins can be secreted from the bacterial cell._________

                ____________________________________________________________________________

            2)_Bacteria may have toxic cell wall components that cause harm when the bacterial cells

 contacts the cells of an organism. ____________

6. What are the two major reasons for decline in diseases? (p. 370)

            1)__Better hygeine__________________________________________

            2)__Improved public health measures (sanitation, water treatment, etc.)

7. What are some good health behaviors to help prevent bacterial infection? (p. 370)

__Washing hands, careful food preparation, attention to water quality __________

____________________________________________________________________________________

8. What is one major public health priority throughout the world to try to fight bacterial disease? (p. 370)

___Installing water treatment systems____________

____________________________________________________________________________________

9. How does your body defend itself against disease? (p. 370)

Skin and mucous lining of mouth, nose, and digestive system provide a barrier to bacteria. Chemical and cellular defenses of the immune system provide protection.

10. Name one way that antibiotics can help people fight disease. (p. 370)

They kill bacteria. Many damage or prevent formation of bacterial cell walls. Other slow or prevent the growth of bacteria.

11. Why is overuse of antibiotics a problem? (p. 370)

They do not affect viruses. Some bacteria can become resistant to antibiotics, and their overuse causes these resistant bacteria to increase their percentages in the population.