What do you think this is?

Vocabulary 10/24 – capsid 10/27 – bacteriophage 10/28 – vaccine 10/29 – helical I can …. 10/24 – Name 2 diseases caused y viruses. 10/27 – Explain why viruses are so hard to kill. 10/28 – Contrast a pandemic and an epidemic 10/29 – Give the science names for red and white blood cells.

REFLECTION

INFECTIOUS DISEASE PATHOGENS – microbes that cause illnesses. Microbes: organisms too small to be seen by the naked eye. Ex: bacteria, protists, and fungi

Bacteria Escherichia coli and Salmonella cause food poisoning. Helicobacter pylori cause gastritis and ulcers. Neisseria meningitidis causes meningitis. Staphylococcus aureus causes a variety of infections in the body, including boils, cellulitis, abscesses, wound infections, toxic shock syndrome, pneumonia, and food poisoning. Streptococcal bacteria cause a variety of infections in the body, including pneumonia, meningitis, ear infections, and strep throat.

Protists Amoeba, african sleeping disease, malaria Leishmaniasis is caused by the Leishmania parasite, which is found in southern Europe, the subtropics and the tropics. This disease is spread by the bites of sand flies that are infected with the parasite. Cutaneous leishmaniasis affects the skin, while visceral leishmaniasis affects the spleen, liver and other organs. Cutaneous leishmaniasis causes skin sores that can change in size and shape as the disease progresses. Visceral leishmaniasis symptoms include weight loss, fever, liver enlargement, spleen enlargement and abnormal blood counts. Toxoplasmosis is caused by an organism known as Toxoplasma gondii, While most people with this disease do not have any symptoms, serious complications can occur when toxoplasmosis develops in people with compromised immune systems. Toxoplasmosis signs and symptoms are flu-like in nature and include body aches, headache, fatigue, fever, swollen lymph nodes and sore throat.

Fungi Athlete foot, mold occidioidomycosis Coccidioidomycosis -- also known as San Joaquin Fever or Valley Fever -- is a fungal disease caused by Coccidioides. This fungus inhabits dry areas, such as Arizona, Nevada, western Texas, central California and some areas of New Mexico. Inhalation of dust contaminated with Coccidioides spores introduces the fungus to the lungs. The Centers for Disease Control and Prevention reports 60 percent of people infected with Coccidioides have no symptoms. In those who develop symptomatic illness, headache, fever, muscle aches, cough and skin rash are common. Although most people recover from coccidioidomycosis within a few weeks, some develop a persistent lung infection or systemic invasion in which the fungi travel to and infect other parts of the body.

Why are viruses not on the list? Are they alive? That’s the question! TWILIGHT CREATURES!!!!

Plant Virus Tobacco Mosiac

Bacteriophage attacking a bacteria!

Virus Noncellular infectious agent Protein wrapped around a nucleic acid core Cannot reproduce itself; can only be reproduced using a host cell

VIRUSES Virus: infectious particle that contains DNA or RNA surrounded by a protein coat that can only reproduce in a host cell. Latin for “poison”.

Viruses consist of a core of nucleic acid, either DNA or RNA, and a protective coat of protein molecules and sometimes lipids(capsid). PARTS OF A VIRUS CAPSID: Protein coat Surrounding the DNA.

Viral Body Plans Genetic material is DNA or RNA Coat is protein Complex virus (bacteriophage) Polyhedral virusHelical virus Fig Page 356

Enveloped Virus (HIV) Fig Page 356 lipid envelope (derived from host) viral RNA reverse transcriptase viral coat (proteins) viral protein

Why is Capsid Important? It is the protein coat around the virus that protests its DNA or RNA. IT IS WAY THEY ARE SO HARD TO KILL!!!!!!

SHAPES!!!!!! ux/deacea6d e93-97a7- 404e19f5809c

EBOLA

Size and Shape of Viruses Viruses come in all shapes sizes. You can only see them with a microscope. 4 shapes of viruses 1.Enveloped – round with spikes( flu viruses) 2.Helical – Long narrow coiled shape(EBOLA rabies) 3.Polyhedral- many sides(foot and mouth disease) 4.COMPLEX - bacteriophages

How do They Name Viruses 1.After the disease they cause. 2.After the organ or tissue they attack 3.Today, they are given a genus name ending in the word virus. Code numbers are given to similar viruses 4.Location discovery

How Do Viruses Attack Their Host Host - Cell the virus attacks. Attaches to the host cell and interlocks with the protein of the host cell. Viruses are very specific to the cells they attack. This helps in the spread of the disease. The outside envelope matches the cell that it attacks. Viruses are specific!

Attacking Host The virus will attach itself to the host cell. It will then shoot its DNA into the host cell. The virus is a parasite that uses the host cell for its energy and reproduction. It is a little different if it is a bacteria cell or eukaryotic cell.

Attacking the host The size and shape of a virus determines which cells or host they can attack.

Viral Multiplication - Basic Steps Attach to host cell Enter host (virus or just genetic material) Direct host to make viral genetic material and protein Assemble viral nucleic acids and proteins Release new viral particles

Virus Attached to Host

What do you Think These Objects are? Are They Living?

Bacteriophages attack bacteria (prokaryotes) viruses attack eukaryotic cells(have a nucleus). viruses attack eukaryotic cells(have a nucleus). Viruses and bacteriophages invade cells and use the host cell's machinery to synthesize more of their own macromolecules. Difference between a bacteriophage and a virus

How Do Vaccines Work A vaccine contains a killed or weakened part of a germ that is responsible for infection. Because the germ has been killed or weakened before it is used to make the vaccine, it can not make the person sick. When a person receives a vaccine, the body reacts by making protective substances called "antibodies". The antibodies are the body's defenders because they help to kill off the germs that enter the body. In other words, vaccines expose people safely to germs, so that they can become protected from a disease but not come down with the disease.

Jenner was operating on the now widely accepted principle that once a person catches a certain disease, he or she is immune to it for the rest of their life. For example, once you've had the chickenpox, it's extremely unlikely that you'll ever catch it again. This is because your body, when exposed again, will recognize the disease and fight it off. The beauty of vaccines is that they help the body develop disease- fighting abilities without making you sick. Vaccines accomplish this amazing feat by tricking the body into believing it already has the full-blown disease. Here are the steps in this process, known as the "immune response":

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Viroids Smaller than viruses Strands or circles of RNA No protein-coding genes No protein coat Cause many plant diseases

Prions Small proteins Linked to human diseases Kuru Kuru Creutzfeldt-Jakob disease (CJD) Creutzfeldt-Jakob disease (CJD) Animal diseases Scrapie in sheep Scrapie in sheep Bovine spongiform encephalopathy (mad cow disease) Bovine spongiform encephalopathy (mad cow disease)

At the boundary of life, between the macromolecules (which are not alive) and the prokaryotic cells (which are), lie the viruses and bacteriophages (phages). These twilight creatures are parasites responsible for causing many diseases in living things (herpes and HIV in humans, for example). Viruses are found everywhere. Are viruses alive? Scientists are still arguing!!!

In isolation, viruses and bacteriophages show none of the expected signs of life. They do not respond to stimuli, they do not grow, they do not do any of the things we normally associate with life.

Characteristics of Living Things Respond to stimulus: virus respond when a cell is near and attaches. Cells: Not cells as we know them Adapt: The viruses do mutate to become stronger but only in a host cell. Reproduces: only in a host cell Energy: Uses energy of the host DNA: Yes they do have their own Grow and develops: Only in host Viruses are parasites that can only perform certain characteristics in host cells. Host: The cell that the virus attaches and uses their DNA and resources.

Vaccine-preventable Diseases Anthrax Cervical Cancer Diphtheria Hepatitis A Hepatitis B Haemophilus influenzae type b Human Papillomavirus Influenza Japanese encephalitis Lyme disease Measles Meningococcal Monkey pox Mumps Pneumococcal Polio Rabies

RotavirusBird Flu Rubella Shingles Smallpox Tetanus Typhoid Tuberculosis Varicella Yellow Fever Common Cold Swine Flu

Prokaryotes and Viruses

Microorganisms Single-celled organisms that are too small to be seen without a microscope Bacteria are the smallest living organisms Viruses are smaller but are not alive

The Prokaryotes Only two groups Archaebacteria and Eubacteria Arose before the eukaryotes

Prokaryotic Characteristics No membrane-bound nucleus Single chromosome Cell wall (in most species) Prokaryotic fission Metabolic diversity

Prokaryotic Body Plan bacterial flagellum pilus capsule cell wall plasma membrane cytoplasm DNA ribosomes in cytoplasm Figure 21.3 Page 348

Bacterial Shapes coccusbacillus spirillum In-text figure Page 348

Metabolic Diversity PhotoautotrophsChemoautotrophsChemoheterotrophs

Bacterial Genes Bacteria have a single chromosome Circular molecule of DNA Circular molecule of DNA Many bacteria also have plasmids Self-replicating circle of DNA that has a few genes Self-replicating circle of DNA that has a few genes Can be passed from one cell to another Can be passed from one cell to another

Prokaryotic Fission - 1 DNA replication begins Bacterium before DNA replication bacterial chromosome Figure 21.7 Page 350

Prokaryotic Fission - 2 parent DNA molecule DNA copy DNA replication completed Membrane growth moves DNA molecules apart Figure 21.7 Page 350

Prokaryotic Fission - 3 New membrane and cell-wall material deposited Cytoplasm divided in two Figure 21.7 Page 350

Conjugation nicked plasmid in donor cell conjugation tube to recipient cell Transfer of plasmid Figure 21.8 Page 351

Prokaryotic Classification EUBACTERIA (Bacteria) ARCHAEBACTERIA (Archaea) EUKARYOTES (Eukarya) Traditionally classified by numerical taxonomy Now increased use of comparative biochemistry Figure 21.9 Page 351

Archaebacteria Methanogens Extreme halophiles Extreme thermophiles

Eubacteria Includes most familiar bacteria Have fatty acids in plasma membrane Most have cell wall; always includes peptidoglycan Classification based largely on metabolism

Eubacterial Diversity Photoautotrophic Aerobic (Cyanobacteria) Aerobic (Cyanobacteria) Anaerobic (Green bacteria) Anaerobic (Green bacteria)Chemoautotrophic Important in nitrogen cycle Important in nitrogen cycleChemoheterotrophic Largest group Largest group

Some Pathogenic Eubacteria Most are chemoheterotrophs E. coli strains E. coli strains Clostridium botulinum Clostridium botulinum Clostridium tetanus Clostridium tetanus Borrelia burgdorferi Borrelia burgdorferi Rickettsia rickettsii Rickettsia rickettsii

Bacterial Behavior Bacteria move toward nutrient-rich regions Aerobes move toward oxygen; anaerobes avoid it Photosynthetic types move toward light Magnetotactic bacteria swim downward Myobacteria show collective behavior

BacteriaVirus 1.OrganellesDNA 2.Kill with antibioticReproduces 3.Reproduces on ownEnergy from 4.Needs energyhost 5. CellMutates 6.Respondshard to kill 7.AdaptsCapsid 8.Grows