MICB 212 Final Exam Study Guide Solutions

MICB 212 Final Exam Study Guide Solutions Main reservoir of Influenza - ANSWERBIRDS! Main reservoir of Poliovirus - ANSWERHUMANS! Targets of Anti-Viral Drugs in HIV - ANSWER1. Protease Inhibitor 2. RT Inhibitor 3. Integrase Inhibitory 4. Entry Inhibitor there is no such thing called exit inhibitor - NA glycoprotein on HIV don't need to be targeted by anti- viral drug because it works on virus egress - no effect ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 2/28 Unique Characteristics of Enterovirus (Poliovirus) - ANSWER- naked virus so stronger than other enveloped virus - highly resistant to acidic pH in gastrointestinal (gut) - highly resistant to acid so it resides in swimming pool - transmitted by fecal- oral route Pathogenesis of Poliovirus - ANSWER- fecal- oral transmission - replicates in the gut (gastrointestinal system) - once poliovirus particle is in blood, it targets CENTRAL NERVOUS SYSTEM (infect nerve cells and kill them) - infected person excretes virus in poop (so it is fecal- oral transmission) Describe polycistronic translation in Poliovirus and how they are cleaved into individual proteins - ANSWER- after polio translation, polypeptide folds into structures and parts of the polyprotein are [proteases] - they become functional - viral protease itself cleaves polio polyprotein into 20 individual proteins (structural + replication proteins) ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 3/28 Virus Genome and Envelopedness of: 1. Poliovirus 2. Influenza 3. HIV - ANSWER1. Poliovirus: (+) ssRNA + naked virus 2. Influenza: 8 segments of (-) RNA, enveloped 3. HIV: 2 identical copies of (+)ssRNA, enveloped Reason why influenza vaccines need to be administered each year - ANSWER- frequent mutations and gene arrangements in viral envelope protein genes - Ab from previous vaccine won't work - due to antigenic drift (minor) + shift (endemic) Why is the dsDNA product from reverse transcribing HIV's +RNA during RT longer in length? - ANSWER- due to RT process - RT reads primer and terminator sequence on RNA and transcribes those as well onto DNA 3 Functions of Reverse Transcriptase (RT enzyme) in HIV replication cycle - ANSWER1. RDDP (RNA dependent DNA pol) - reads (+)ssRNA and makes ssDNA 2, RNAse H - degrades RNA in RNA:DNA hybrid ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 4/28 3. DDDP (DNA - dependent DNA pol) - reads ssDNA and makes it into dsDNA Anti-Viral Therapy/Drugs (vProtein inhibitors) in Influenza and HIV - ANSWERInfluenza: 1. NA Inhibitor (ex. Tamiflu) - blocks NA protein from cleaving SA - inhibits virus to infect new cells - prevents spreading 2. Ion Channel Inhibitor - blocks H+ to acidify endosome - no fusion of endosome + envelope in influenza HIV: - protease inhibitor, RT inhibitor, integrase inhibitor, entry inhibitor, etc.. List proteins encoded by each gene in HIV virus: gag, pol and env - ANSWER1. gag - structural proteins (capsid, nucleocapsid, matrix) ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 5/28 - protease (used in HIV maturation) 2. pol - RTase & INase 3. env - envelope glycoproteins (gp120 and gp41) Which DNA strand of HIV dsDNA (after RT) is integrated into host cell DNA for transcription? Why? - ANSWER(-) DNA strand integrated into host cell DNA - so that transcription gives +RNA = mRNA for translation Which proteins are PACKAGED in CORE of HIV virus? - ANSWER- RTase, INase - because RT occurs inside virus core once virus enters cytoplasm *protease is packaged outside core (between core and matrix) - because protease is used once virus buds out + during matu