1Lecture 11:STD’s and Viruses in CellsBasic Structural Organization• Membrane• Cytoplasm• NucleusCell MembraneFluid Mosaic Model-Fluid- kind of like a bubble-Mosaic- Full of “Stuff”1. Phospholipids (of course)2. Protein (Oh no not again!)3. Sterols- Structurally Important-Not long chains-Add flexibility to membraneReceptors and RecognitionReceptors are sensors on the cell-Nutrient levels-Status of surrounding cells-Divide or Die-Activate or Suppress Recognition-ID tags-Immune surveillance Cell MembraneKey ConceptsThe membrane is an organelleThe membrane is dynamicMembranes play a key role in cell function• More than just a filmy covering• Not just on the outsideInside the CellMore Membranes!OrganellesFew Empty SpacesCytoplasm is the Desert in the Cell2Endomembrane System1. Nuclear Membrane2. Endoplasmic Reticulum (ER)Rough ERSmooth ER3. The Golgi Body4. Vessicles5. Sarcoplasmic ReticulumEndomembrane SystemNuclear Membrane– Inner nuclear membrane– Outter nuclear membrane• Continuous with ER• Nuclear Membrane Proteins– Nuclear Lamina- Inner membrane• Structure• Role in Division– Nuclear pores- TransportNuclear Pore Function Endomembrane SystemEndoplasmic Reticulum• Site of Protein Synthesis– Ribosomes- attached vs. “free”– Protein tags for trafficking:• Outside, Inside or in the Middle• Inside the ER– Post-Transcriptional Modification• Glycosylation- sugar additions• Glycosylation labels proteins for transport – Transport• New proteins shuttled to Golgi or VessiclesEndomembrane SystemGolgi Apparatus• More post-transcriptional modification• Sorting and transport– Default transport and Direction• If in doubt secrete it• Carbohydrate Synthesis– Polysaccharides• Pectin and hemicellulose• GlycosaminoglycansEndomembrane SystemVessiclesSecretory Vessicles-Fuse with membrane and dump contentsLysosome and Peroxisome-Degrade and recycleVacuoles-Storage containers3• Protein made in the ER is folded• Bits of the ER are transported to the Golgi• The Golgi labels and sorts proteins• Bits of the Golgi are transported to “vessicles”– Secretory vessicles– LysosomeProtein TrafficGolgiERRecognitionRecognizing cells with viral infectionsEndomembrane SystemWhat Happens in Each Compartment1. ER 2. Golgi3. Vessicles– Follow the proteinBasic Structural Organization• Membrane• Cytoplasm• NucleusMembrane-bound OrganellesNucleusMitochondriaChloroplastSexually Transmitted DiseaseChlamydiaGonorrheaSyphillisTrichomonasGenital WartsHerpes VirusHIV/AIDS4ChlamydiaCauseIntracellular bacteriaSymptoms (M):Urethritis, epididymitis, prostitis (mild to severe burning)Symptoms (F):Urethritis, cervicitisand PID.Key featuresImportant cause of infertilityNo external soresAsymptomatic:Up to 20% Incubation:1-3 weeksTreatment:AntibioticsCDC STD survalience 2002 http://www.cdc.gov/std/stats/chlamydia.htmChlamydia•Most prevalent of all STDs•Infection can facilitate the transmission of HIV infection•A major cause of infertility, ectopicpregnancy, and chronic pelvic pain•pregnant women infected with chlamydiapass infection to infants during delivery, results in neonatal ophthalmia (eyes) and pneumonia (lungs)GonorrheaCauseIntracellular bacteriaSymptoms (M):Urethritis (mild to severe burning)Symptoms (F):Urethritis, cervicidis and PID.Symptoms (M/F):30-50% rectal infectionPharyngitis, isolated from pharynx (throat)Important cause of infertilityKey featuresScaring in falopian tubes increases chance of ectopicpregnancyNo external soresAsymptomatic:Up to 20% Incubation:3 days to 3 weeksTreatment:AntibioticsIncreasing incidence of bacterial resistance to effective antibioticsCDC STD survalience 2002 http://www.cdc.gov/std/stats/chlamydia.htmGonorrhea•Major cause of pelvic inflammatory disease (PID) in the US•PID leads to serious outcomes:•tubal infertility•ectopic pregnancy•chronic pelvic pain•Strong evidence thatgonococcal infections facilitate the transmission of HIV infectionSyphilisCause:Bacteria, spirocheteSymptoms (M/F)Primary:Chancre (painless)Secondary:Headache, fever, sore throat, rash- trunk to palms and soles.Tertiary:Nervous system and cardiovascular damage.Leads to: meningitis, dementia, neuropathy and heart attackKey FeaturesIncubation: 21 daysPrimary symptoms: 3-6 weeks, Secondary symptoms: for 3-6 weeks, 3-6 weeks after primary, spontaneously resolveTertiary symptoms: years after infectionTreatment: most successful in first and secondary stagesCause:Flagellated protozoanSymptoms (M):Asymptomatic, sporadic urethritisSymptoms (F):Vaginosis with discharge (frothy green) and abdominal painKey Features:Non-bacterial parasiteIncubation:3 to 28 daysTrichomonas5Trichomonas•Trichomoniasis is one of the most common sexually transmitted diseases•Mainly affects 16-to-35-year old women. •In the United States, it is estimated that 2 million women become infected each year.http://www.cdc.gov/ncidod/dpd/parasites/trichomonas/factsht_trichomonas.htmGenital WartsCause:Human papilloma virus (HPV =DNA virus)Symptoms (M/F)PainlessCoalesced condylomate may cause discomfort from size and locationA appear as flat, smooth, small bumps, or quite large, pink, cauliflower-like lumps.Key FeaturesCorrelated with cancerTreatment:CryotherapyDifficult to distinguished Asymtomatic (F) detection with PAP smearAsymtomatic (M) no HPV test for menGenital WartsHPV infects the genital area and is spread through genital contact.Most HPV infections have no signs or symptoms; therefore, most infected persons are unaware they are infected, yet they can transmit the virus to a sex partnerInitial visits to physicians’ offices: United States, 1966–2002Herpes VirusCauseHerpes Virus (DNA virus)Symptoms (M/F)Fever, headache, retention, swollen lymphnodes. Genital soresKey FeaturesLifelong recurrent episodes of painful genital lesions, 4 or 5 each yearIncreased likelihood of HIV transmission and acquisitionWomen who acquire genital herpes in pregnancy: potentially fatal neonatal infectionIncubation: 8 to 16 daysHerpes VirusHerpes simplex I and II: Cold sores vs. STDsHerpes can make people more susceptible to HIV infection, and it can make HIV-infected individuals more infectious.There is no treatmentthat can cure herpesEpidemic? – Nationwide, one out of five– Between the late 1970s and the early1990s, increasedby 30%Herpes simplex virus type 2 infections — Percent seroprevalence according to age in NHANES II (1976-1980) and NHANES III
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