VIRUSESVIRUSESAND HIVAND HIV

VIRAL VOCABULARYVIRAL VOCABULARY

BacteriophageBacteriophage PathogenPathogen Lytic cycleLytic cycle Lysogenic cycleLysogenic cycle PrionPrion ViroidViroid Vaccination Vaccination

ImmunityImmunity

Read (942-943) Vaccinations(939) STDs (1018-1020)

I. ANATOMYI. ANATOMY

DRAW AND LABEL

/DNA

spikes

* Must attach to a specific receptor site

DRAW AND LABEL

Viral Anatomy

DNA or RNA

Contractile Sheath

Influenza Virus Strains

AdenovirusAdenovirus A group of viruses that A group of viruses that

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

II. ARE THEY ALIVE???II. ARE THEY ALIVE??? Obligate Intracellular ParasitesObligate Intracellular Parasites – –

must get inside a host to functionmust get inside a host to function Non-cellular – no cytoplasm, no Non-cellular – no cytoplasm, no

membranemembrane No digestion, respiration, movementNo digestion, respiration, movement REPRODUCTION!!!!!!! – they are good at REPRODUCTION!!!!!!! – they are good at

it!it!– Not by mitosis or meiosisNot by mitosis or meiosis– Only when associated with another cellOnly when associated with another cell

GENETIC MATERIAL – DNA or RNAGENETIC MATERIAL – DNA or RNA

III. HOW DO THEY WORK?III. HOW DO THEY WORK?

See lab on Viral ReplicationSee lab on Viral Replication DNA vs. RNA VIRUSDNA vs. RNA VIRUS DNA (after invasion)DNA (after invasion)

1.1. Joins host DNA and produces viral RNA Joins host DNA and produces viral RNA and viral proteinsand viral proteins

oror

2.2. Remains free and produces viral RNA Remains free and produces viral RNA and viral proteinsand viral proteins

HOW DO THEY WORK HOW DO THEY WORK (cont.)(cont.)

RNA – RetrovirusRNA – Retrovirus Usual flow of information – Usual flow of information –

DNA>RNA>ProteinDNA>RNA>Protein Retroviruses – RNA>DNA>into our cells Retroviruses – RNA>DNA>into our cells

DNA – uses reverse transcriptase (RT)DNA – uses reverse transcriptase (RT) Join ribosomes in cytoplasm and produce Join ribosomes in cytoplasm and produce

viral proteinsviral proteinsOROR

With the help of RT, RNA makes DNA, With the help of RT, RNA makes DNA, which gets into the host cell’s DNA – new which gets into the host cell’s DNA – new RNA is produced and acts as aboveRNA is produced and acts as above

HIV– MODERN DAY HIV– MODERN DAY PIRATEPIRATE

HIVHIV – HUMAN IMMUNODEFICIENCY VIRUS – HUMAN IMMUNODEFICIENCY VIRUS AIDSAIDS – ACQUIRED IMMUNE DEFICIENCY – ACQUIRED IMMUNE DEFICIENCY

SYNDROMESYNDROME 3 AREAS SERIOUSLY AFFECTED – ASIA, S. 3 AREAS SERIOUSLY AFFECTED – ASIA, S.

AMERICA, AFRICAAMERICA, AFRICA DRAW AN LABEL VIRUSDRAW AN LABEL VIRUS METHODS OF TRANSMISSIONMETHODS OF TRANSMISSION – BLOOD, SEMEN, – BLOOD, SEMEN,

VAGINAL/CERVIAL SECRETIONS, BREAST MILK, PUSVAGINAL/CERVIAL SECRETIONS, BREAST MILK, PUS TARGET CELL OF HIVTARGET CELL OF HIV – CD4+ T HELPER CELL – CD4+ T HELPER CELL OPPORTUNISTIC INFECTIONOPPORTUNISTIC INFECTION – A NORMAL – A NORMAL

HARMLESS ORGANISM THAT WHEN IT ENTERS THE HARMLESS ORGANISM THAT WHEN IT ENTERS THE BODY OF A PERSON WITH A WEAK IMMUNE BODY OF A PERSON WITH A WEAK IMMUNE SYSTEM, IT CAN HARM OR KILL THEMSYSTEM, IT CAN HARM OR KILL THEM

HIV – TIME COURSE TO AIDSHIV – TIME COURSE TO AIDS

Obligate Obligate Intracellular Intracellular

ParasiteParasite – – microorganisms that can microorganisms that can

only reproduce if they have only reproduce if they have entered another organism's entered another organism's

cell - all virusescell - all viruses

CD4 ReceptorCD4 Receptor – – a special receptor on a host a special receptor on a host cell's surface that HIV uses to cell's surface that HIV uses to

infiltrate the cell infiltrate the cell

Reverse TranscriptaseReverse Transcriptase – –the enzyme produced by HIV the enzyme produced by HIV and other retroviruses that and other retroviruses that

allows them to synthesize DNA allows them to synthesize DNA from their RNA, which is then from their RNA, which is then

integrated into the integrated into the chromosomes of the host cell.chromosomes of the host cell.

T-Helper LymphocyteT-Helper Lymphocyte – –target cell in the immune target cell in the immune

system for HIVsystem for HIV

HIV virus attacking and infecting a Helper T-cell

IV. REPRODUCTIONIV. REPRODUCTION LYTIC CYCLE – REPRODUCTIVE CYCLE LYTIC CYCLE – REPRODUCTIVE CYCLE

OF THE VIRUS – virulent (disease OF THE VIRUS – virulent (disease causing) – active phasecausing) – active phase

1.1. Absorption – attachment to receptor siteAbsorption – attachment to receptor site

2.2. Entry – insertion of genetic materialEntry – insertion of genetic material

3.3. Replication – viral parts are made – capsid Replication – viral parts are made – capsid and nucleic acidsand nucleic acids

4.4. Assembly – separate parts are put Assembly – separate parts are put togethertogether

5.5. Release – digest cell membrane and Release – digest cell membrane and escape (destroys host cell in the processescape (destroys host cell in the process

LYSOGENIC CYCLELYSOGENIC CYCLE Temperate virus – does not cause Temperate virus – does not cause

disease immediately - virus hides outdisease immediately - virus hides out Resides in the cell without replicating. Resides in the cell without replicating.

The cell may divide and result in many The cell may divide and result in many cells with the viral genetic material cells with the viral genetic material insideinside

Will lead to lytic cycle eventuallyWill lead to lytic cycle eventually HIV spend the majority of the time in HIV spend the majority of the time in

this cyclethis cycle

VIRAL REPLICATION LABVIRAL REPLICATION LAB

LAB LAB ANSWERS…ANSWERS…

V. Relatives of VirusesV. Relatives of Viruses

Viroids – short strands of RNA, no capsidViroids – short strands of RNA, no capsid Prions – glycoproteins containing a Prions – glycoproteins containing a

polypeptide of 250 amino acids. polypeptide of 250 amino acids. – A protein capable of replicationA protein capable of replication– Infectious protein…no nucleic acidInfectious protein…no nucleic acid– Causes Mad Cow disease, scrappies in Causes Mad Cow disease, scrappies in

sheep, and Kuru in New Guineasheep, and Kuru in New Guinea

PicturesPictures

VIROIDS PRIONS

MAD COW DISEASE (BSE)MAD COW DISEASE (BSE)

During WWIIDuring WWII

Sheep parts were cooked and mixed Sheep parts were cooked and mixed in cow feedin cow feed

Cooking didn’t destroy “scrapie” Cooking didn’t destroy “scrapie” prion prion

Cows were infected with prionCows were infected with prion Cows get BSE “mad cow” diseaseCows get BSE “mad cow” disease Can it be passed to humans?Can it be passed to humans?

Fore people of New Fore people of New GuineaGuinea

VI. VACCINES – VI. VACCINES – preventions…not a curepreventions…not a cure

Immune System – responds to foreign Immune System – responds to foreign proteins (bacteria, virus, organ proteins (bacteria, virus, organ transplant, blood transfusion, bee venom, transplant, blood transfusion, bee venom, peanuts, pollen) – fever, swelling, peanuts, pollen) – fever, swelling, increased mucus secretions, allergies…increased mucus secretions, allergies…etc.etc.

Inoculation – injection withInoculation – injection with a non-replicating virus or a non-replicating virus or viral partsviral parts

Antibodies – formed by the body to the Antibodies – formed by the body to the specific foreign protein and seeks to specific foreign protein and seeks to destroy them…this is why you cannot get destroy them…this is why you cannot get sick with the same cold twicesick with the same cold twice

Antibodies continue to be produced Antibodies continue to be produced indefinitely and remain to protect in the indefinitely and remain to protect in the event of a second exposure to the real event of a second exposure to the real disease causing virusdisease causing virus

Immunity – your body mounting a response Immunity – your body mounting a response against a foreign antigen protein...attacks against a foreign antigen protein...attacks and destroys the foreign substanceand destroys the foreign substance

QUIZ TOPICSQUIZ TOPICS

HIV/AIDS, Video stuffHIV/AIDS, Video stuff Text 450-459, 942-943, 939, 1018-Text 450-459, 942-943, 939, 1018-

10201020 VocabVocab Living/Nonliving WSLiving/Nonliving WS Lab on ReproductionLab on Reproduction Anatomy, Reproduction, Immunity, Anatomy, Reproduction, Immunity,

prion vs. viroid, vaccinesprion vs. viroid, vaccines

Jeopardy Questions - EasyJeopardy Questions - Easy

HIV Stands for….HIV Stands for…. Your immune system responds to ______.Your immune system responds to ______. How soon after exposure to HIV are you How soon after exposure to HIV are you

infectious?infectious? Define obligate intracellular parasite.Define obligate intracellular parasite. Name 3 diseases caused by viruses.Name 3 diseases caused by viruses. What is an opportunistic infection?What is an opportunistic infection? Why would a virus be considered Why would a virus be considered

nonliving?nonliving? What is the target cell for HIV?What is the target cell for HIV?

Jeopardy Questions - EasyJeopardy Questions - Easy HIV Stands for…. HUMAN IMMUNEDEFICIENCY VIRUSHIV Stands for…. HUMAN IMMUNEDEFICIENCY VIRUS Your immune system responds to FOREIGN PROTEINSYour immune system responds to FOREIGN PROTEINS How soon after exposure to HIV are you infectious? How soon after exposure to HIV are you infectious?

IMMEDIATELYIMMEDIATELY Define obligate intracellular parasite. MUST LIVE IN A Define obligate intracellular parasite. MUST LIVE IN A

HOST TO SURVIVE AND REPRODUCEHOST TO SURVIVE AND REPRODUCE Name 3 diseases caused by viruses. MEASELS, MUMPS, Name 3 diseases caused by viruses. MEASELS, MUMPS,

RABIES, HIV, FLU, COLD, SMALL POX, CHICKEN POXRABIES, HIV, FLU, COLD, SMALL POX, CHICKEN POX What is an opportunistic infection? ONLY HARMS WHEN What is an opportunistic infection? ONLY HARMS WHEN

IMMUNE SYSTEM IS WEAKIMMUNE SYSTEM IS WEAK Why would a virus be considered nonliving? NON-Why would a virus be considered nonliving? NON-

CELLULARCELLULAR What is the target cell for HIV? T-HELPER LYMPHOCYTEWhat is the target cell for HIV? T-HELPER LYMPHOCYTE

Jeopardy Questions - Jeopardy Questions - MediumMedium

What is the main difference b/t prion What is the main difference b/t prion and a viroid?and a viroid?

Name 3 non-sexual fluids that carry Name 3 non-sexual fluids that carry HIV?HIV?

What do AIDS victims typically die What do AIDS victims typically die from?from?

AIDS stands for?AIDS stands for? What part of the virus attaches itself to What part of the virus attaches itself to

the host cell?the host cell?

Jeopardy Questions - Jeopardy Questions - MediumMedium

What is the main difference b/t prion and What is the main difference b/t prion and a viroid? PROTEIN VS. RNA STRANDa viroid? PROTEIN VS. RNA STRAND

Name 3 non-sexual fluids that carry HIV? Name 3 non-sexual fluids that carry HIV? MOTHER’S MILK, BLOOD, PUSMOTHER’S MILK, BLOOD, PUS

What do AIDS victims typically die from?What do AIDS victims typically die from? OPPORTUNISTIC INFECTIONS

AIDS stands for? ACQUIRED AIDS stands for? ACQUIRED IMMUNEDEFICIENCY SYNDROMEIMMUNEDEFICIENCY SYNDROME

What part of the virus attaches itself to What part of the virus attaches itself to the host cell? TAIL FIBERSthe host cell? TAIL FIBERS

Jeopardy Questions - Jeopardy Questions - DifficultDifficult

What does the AIDS test really test for? What does the AIDS test really test for? Why is it not accurate for up to 6 Why is it not accurate for up to 6 months?months?

How does a vaccine work?How does a vaccine work? Contrast lytic vs. lysogenic cycle.Contrast lytic vs. lysogenic cycle. What is the function of the reverse What is the function of the reverse

transcriptase enzyme?transcriptase enzyme? Name the 3 places most seriously Name the 3 places most seriously

affected by AIDS (globally).affected by AIDS (globally).

Jeopardy Questions - Jeopardy Questions - DifficultDifficult What does the AIDS test really test for? ANTIBODIES What does the AIDS test really test for? ANTIBODIES

Why is it not accurate for up to 6 months? TAKES Why is it not accurate for up to 6 months? TAKES THAT LONG FOR ENOUGH TO BE PRODUCEDTHAT LONG FOR ENOUGH TO BE PRODUCED

How does a vaccine work?How does a vaccine work? EXPOSE YOU TO A NON-INFECTIOUS FORM OF THE ORGANISM AND CAUSE YOUR IMMUNE SYSTEM TO MAKE ANTIBODIES IF YOU ARE EXPOSED LATER YOUR BODY IS READY

Contrast lytic vs. lysogenic cycle.Contrast lytic vs. lysogenic cycle. What is the function of the reverse transcriptase What is the function of the reverse transcriptase

enzyme?enzyme? Name the 3 places most seriously affected by AIDS Name the 3 places most seriously affected by AIDS

(globally).(globally).

Contrast lytic vs. lysogenic cycle.Contrast lytic vs. lysogenic cycle. LYTIC IS THE IMMEDIATE REPLICATION OF THE VIRUS

What is the function of the reverse What is the function of the reverse transcriptase enzyme? CONVERT transcriptase enzyme? CONVERT RNA TO DNARNA TO DNA

Name the 3 places most seriously Name the 3 places most seriously affected by AIDS (globally).affected by AIDS (globally). AFRICA, S and Central America, Asia and SE ASIA

A COUPLE MORE A COUPLE MORE QUESTIONSQUESTIONS

1. Give 3 reasons why some one may say that a virus is alive.

2. Why can’t a doctor prescribe antibiotics for a virus?

3. Describe the brief history of Mad Cow Disease