VIRUSES AND HIV

VIRAL VOCABULARY Read (942-943) Vaccinations(939) STDs (1018-1020) Bacteriophage Pathogen Lytic cycle Lysogenic cycle Prion Viroid Vaccination Immunity Read (942-943) Vaccinations(939) STDs (1018-1020)

I. ANATOMY DRAW AND LABEL spikes /DNA * Must attach to a specific receptor site DRAW AND LABEL

DRAW AND LABEL

Viral Anatomy DNA or RNA Contractile Sheath

Influenza Virus Strains

Adenovirus A group of viruses that infect the membranes (tissue linings) of the respiratory tract, the eyes, the intestines, and the urinary tract, adenoviruses account for about 10% of acute respiratory infections in children and are a frequent cause of diarrhea.

II. ARE THEY ALIVE??? Obligate Intracellular Parasites – must get inside a host to function Non-cellular – no cytoplasm, no membrane No digestion, respiration, movement REPRODUCTION!!!!!!! – they are good at it! Not by mitosis or meiosis Only when associated with another cell GENETIC MATERIAL – DNA or RNA

III. HOW DO THEY WORK? See lab on Viral Replication DNA vs. RNA VIRUS DNA (after invasion) Joins host DNA and produces viral RNA and viral proteins or Remains free and produces viral RNA and viral proteins

HOW DO THEY WORK (cont.) RNA – Retrovirus Usual flow of information – DNA>RNA>Protein Retroviruses – RNA>DNA>into our cells DNA – uses reverse transcriptase (RT) Join ribosomes in cytoplasm and produce viral proteins OR With the help of RT, RNA makes DNA, which gets into the host cell’s DNA – new RNA is produced and acts as above

HIV– MODERN DAY PIRATE HIV – HUMAN IMMUNODEFICIENCY VIRUS AIDS – ACQUIRED IMMUNE DEFICIENCY SYNDROME 3 AREAS SERIOUSLY AFFECTED – ASIA, S. AMERICA, AFRICA DRAW AN LABEL VIRUS METHODS OF TRANSMISSION – BLOOD, SEMEN, VAGINAL/CERVIAL SECRETIONS, BREAST MILK, PUS TARGET CELL OF HIV – CD4+ T HELPER CELL OPPORTUNISTIC INFECTION – A NORMAL HARMLESS ORGANISM THAT WHEN IT ENTERS THE BODY OF A PERSON WITH A WEAK IMMUNE SYSTEM, IT CAN HARM OR KILL THEM

HIV – TIME COURSE TO AIDS

Obligate Intracellular Parasite – microorganisms that can only reproduce if they have entered another organism's cell - all viruses

CD4 Receptor – a special receptor on a host cell's surface that HIV uses to infiltrate the cell

Reverse Transcriptase – the enzyme produced by HIV and other retroviruses that allows them to synthesize DNA from their RNA, which is then integrated into the chromosomes of the host cell.

T-Helper Lymphocyte – target cell in the immune system for HIV

HIV virus attacking and infecting a Helper T-cell

IV. REPRODUCTION LYTIC CYCLE – REPRODUCTIVE CYCLE OF THE VIRUS – virulent (disease causing) – active phase Absorption – attachment to receptor site Entry – insertion of genetic material Replication – viral parts are made – capsid and nucleic acids Assembly – separate parts are put together Release – digest cell membrane and escape (destroys host cell in the process

LYSOGENIC CYCLE Temperate virus – does not cause disease immediately - virus hides out Resides in the cell without replicating. The cell may divide and result in many cells with the viral genetic material inside Will lead to lytic cycle eventually HIV spend the majority of the time in this cycle

VIRAL REPLICATION LAB

LAB ANSWERS…

V. Relatives of Viruses Viroids – short strands of RNA, no capsid Prions – glycoproteins containing a polypeptide of 250 amino acids. A protein capable of replication Infectious protein…no nucleic acid Causes Mad Cow disease, scrappies in sheep, and Kuru in New Guinea

Fore people of New Guinea

Pictures VIROIDS PRIONS

MAD COW DISEASE (BSE)

VI. VACCINES – preventions…not a cure Immune System – responds to foreign proteins (bacteria, virus, organ transplant, blood transfusion, bee venom, peanuts, pollen) – fever, swelling, increased mucus secretions, allergies…etc. Inoculation – injection with a non-replicating virus or viral parts

Antibodies – formed by the body to the specific foreign protein and seeks to destroy them…why you cannot get sick with the same cold twice Antibodies continue to be produced indefinitely and remain to protect in the event of a second exposure to the real disease causing virus Immunity – your body mounting a response against a foreign antigen protein...attacks and destroys the foreign substance

QUIZ TOPICS HIV/AIDS, Video stuff Text 450-459, 942-943, 939, 1018-1020 Vocab Living/Nonliving WS Lab on Reproduction Anatomy, Reproduction, Immunity, prion vs. viroid, vaccines

Jeopardy Questions - Easy HIV Stands for…. Your immune system responds to ______. How soon after exposure to HIV are you infectious? Define obligate intracellular parasite. Name 3 diseases caused by viruses. What is an opportunistic infection? Why would a virus be considered nonliving? What is the target cell for HIV?

Jeopardy Questions - Medium What is the main difference b/t prion and a viroid? Name 3 non-sexual fluids that carry HIV? What do AIDS victims typically die from? AIDS stands for? What part of the virus attaches itself to the host cell?

Jeopardy Questions - Difficult What does the AIDS test really test for? Why is it not accurate for up to 6 months? How does a vaccine work? Contrast lytic vs. lysogenic cycle. What is the function of the reverse transcriptase enzyme? Name the 3 places most seriously affected by AIDS (globally).