Virology Quiz: Virus Families and Structures
45 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

The pathogenic human virus ______ belongs to the Coronavirus family.

Coronavirus

The human ______ virus is classified under the Orthomyxoviridae family.

influenza

Respiratory Syncytial Virus (RSV) belongs to the ______ family.

Paramyxoviridae

The ______ virus is part of the Adenoviridae family and can cause a variety of illnesses.

<p>Adenovirus</p> Signup and view all the answers

HIV-1 is a pathogenic retrovirus that affects the ______ system.

<p>immune</p> Signup and view all the answers

Papillomaviridae family includes viruses that can lead to ______ in certain cases.

<p>cancer</p> Signup and view all the answers

The pathogenic human hepatitis viruses include HVA, HVB, and ______.

<p>HVC</p> Signup and view all the answers

Understanding the ______ of a virus involves studying its structure and how it replicates in host cells.

<p>taxonomy</p> Signup and view all the answers

Viral ______ encodes all the information necessary to produce new progeny virions.

<p>nucleic acid</p> Signup and view all the answers

The ______ is a protein shell that protects the viral nucleic acid between infections.

<p>capsid</p> Signup and view all the answers

Examples of ______ proteins include matrix and nucleocapsid proteins.

<p>structural</p> Signup and view all the answers

______ proteins are required for viral replication and assembly.

<p>Non-structural</p> Signup and view all the answers

The viral ______ is a lipid bilayer that aids in cell membrane penetration.

<p>envelope</p> Signup and view all the answers

Approximately ______% of acute respiratory disease cases are caused by viral infections.

<p>80</p> Signup and view all the answers

Respiratory disease accounts for an estimated ______% to 80% of all acute morbidity in the United States.

<p>75</p> Signup and view all the answers

Major causes of acute respiratory disease include influenza viruses and ______.

<p>coronaviruses</p> Signup and view all the answers

HIV-1 has a surface protein called ______ that binds to the CD4 receptor on T cells.

<p>gp120</p> Signup and view all the answers

______ is the receptor that the influenza virus's HA protein binds to in respiratory epithelial cells.

<p>Sialic acid</p> Signup and view all the answers

The E2 gene encodes a transcription factor that regulates the transcription of HPV E6 and E7 ______.

<p>oncoproteins</p> Signup and view all the answers

In the absence of E2, increased synthesis of E6 and E7 ______ occurs.

<p>protein</p> Signup and view all the answers

E6 binds to ______ in the cytosol and recruits the E6AP ubiquitin ligase.

<p>p53</p> Signup and view all the answers

HPV E7 binds to ______ in the cytosol, promoting proteosomal degradation.

<p>pRb</p> Signup and view all the answers

Loss of cellular ______ and pRb tumor suppressor proteins allows a cell with DNA damage to divide.

<p>p53</p> Signup and view all the answers

No viral replication occurs in transformed cells, so the cell's energy goes to ______.

<p>hyperproliferation</p> Signup and view all the answers

Microscopically, excess production of ______ indicates hyperkeratosis.

<p>keratin</p> Signup and view all the answers

Coronaviruses are the largest ______ viruses.

<p>RNA</p> Signup and view all the answers

The virus replicates in the cytoplasm using its newly synthesized viral RNA ______.

<p>polymerase</p> Signup and view all the answers

SARS-CoV-2 is transmitted through respiratory ______.

<p>droplets</p> Signup and view all the answers

The Spike (S) glycoprotein of SARS-CoV-2 interacts with the ______ receptor.

<p>ACE2</p> Signup and view all the answers

Three novel human coronaviruses include SARS-CoV-1, MERS-CoV, and SARS-CoV-______.

<p>2</p> Signup and view all the answers

MERS was highly fatal, with an approximate death rate of ______%.

<p>35</p> Signup and view all the answers

COVID-19 became a pandemic infection causing approximately ______ million cases globally.

<p>178</p> Signup and view all the answers

Molecular (RT-PCR) and antigen tests are available to detect SARS-CoV-______.

<p>2</p> Signup and view all the answers

______ was limited in spread compared to COVID-19 despite being highly fatal.

<p>SARS</p> Signup and view all the answers

The virus acquires an envelope from ER-______ membranes.

<p>Golgi</p> Signup and view all the answers

The upper respiratory tract includes the ______, nasal cavity, and pharynx.

<p>larynx</p> Signup and view all the answers

In the upper respiratory tract, the epithelium consists of taller epithelial cells with ______ and mucus-producing cells.

<p>cilia</p> Signup and view all the answers

The lower respiratory tract includes structures such as bronchi, bronchioles, and ______.

<p>alveoli</p> Signup and view all the answers

As cells transition from the upper to the lower respiratory tract, they become ______ and lose cilia/mucus-producing cells.

<p>shorter</p> Signup and view all the answers

SARS-CoV-2 enters the body via the respiratory tract and nasopharyngeal or ______ cells.

<p>oropharyngeal</p> Signup and view all the answers

The viral spike glycoprotein's receptor binding domains bind to the ______ receptor.

<p>ACE2</p> Signup and view all the answers

ACE2 receptors are found in the respiratory system, kidney, and ______ of the heart.

<p>myocardium</p> Signup and view all the answers

The function of the upper respiratory epithelium is to help clean inhaled air by trapping debris in ______.

<p>mucus</p> Signup and view all the answers

The shorter cells in the lower respiratory epithelium help promote better diffusion of ______ and carbon dioxide.

<p>oxygen</p> Signup and view all the answers

The upper respiratory tract is responsible for utilizing ______ to move trapped debris towards the gastrointestinal tract.

<p>cilia</p> Signup and view all the answers

Flashcards

Coronavirus

Pathogenic virus family affecting humans, causes respiratory diseases.

Influenza Virus

Pathogenic virus from Orthomyxoviridae family; causes flu, spreads easily.

RSV (Respiratory Syncytial Virus)

Paramyxoviridae family virus, major cause of respiratory infections in children.

Adenovirus

Pathogenic virus related to respiratory illnesses; can cause conjunctivitis.

Signup and view all the flashcards

Retroviruses

Viral family including HIV-1; integrates into host DNA, leading to chronic infections.

Signup and view all the flashcards

Papillomaviridae

Virus family that includes HPV; some strains linked to cancer.

Signup and view all the flashcards

Hepatitis Viruses

Family of viruses affecting human liver; includes HAV, HBV, HCV.

Signup and view all the flashcards

Stages of Viral Infection

Phases of infection: transmission, replication, cellular effects, and immune response.

Signup and view all the flashcards

SARS-CoV-2

The virus causing COVID-19; transmitted via respiratory droplets.

Signup and view all the flashcards

Spike glycoprotein

Protein on corona virus surface that binds to ACE2 receptor.

Signup and view all the flashcards

ACE2 receptor

Cell receptor that SARS-CoV-2 binds to for entry.

Signup and view all the flashcards

RT-PCR Test

Molecular test that detects SARS-CoV-2 RNA in patients.

Signup and view all the flashcards

Antigen Test

Test detecting specific proteins from SARS-CoV-2.

Signup and view all the flashcards

Epidemic vs Pandemic

Epidemic is localized; pandemic spreads globally (e.g., COVID-19).

Signup and view all the flashcards

MERS-CoV

Virus causing Middle East Respiratory Syndrome; high fatality rate.

Signup and view all the flashcards

Viral replication

Process where virus produces new viruses inside host cells.

Signup and view all the flashcards

Erythroid precursor cells

Immature red blood cells affected by Parvovirus B19.

Signup and view all the flashcards

Upper Respiratory Tract

The respiratory system area above the larynx, includes sinuses, nasal cavity, and pharynx.

Signup and view all the flashcards

Function of Upper Respiratory Epithelium

Taller cells with cilia and mucus that clean inhaled air by trapping debris.

Signup and view all the flashcards

Lower Respiratory Tract

The region below the larynx, includes bronchi, bronchioles, and alveoli.

Signup and view all the flashcards

Function of Lower Respiratory Epithelium

Shorter cells that help in the diffusion of oxygen and carbon dioxide.

Signup and view all the flashcards

SARS-CoV-2 Entry Points

The virus enters primarily via upper respiratory and oropharyngeal cells.

Signup and view all the flashcards

Viral Spike Glycoprotein

The protein that binds SARS-CoV-2 to ACE2 receptor to facilitate entry.

Signup and view all the flashcards

Bronchial Epithelium

The epithelial layer of the bronchi involved in the response to viral infections.

Signup and view all the flashcards

Alveolar Macrophages

Immune cells in the alveoli that help clear pathogens and debris.

Signup and view all the flashcards

Alveolar Epithelial Cells

Cells lining the alveoli that facilitate gas exchange in the lungs.

Signup and view all the flashcards

E2 gene

Gene encoding a transcription factor regulating HPV E6 and E7 oncoproteins.

Signup and view all the flashcards

HPV E6 protein

Oncoprotein binding to p53, leading to its degradation.

Signup and view all the flashcards

p53 protein

Tumor suppressor protein that prevents cell division with DNA damage.

Signup and view all the flashcards

Nucleic acid

Encodes information necessary to produce new virions (viral particles).

Signup and view all the flashcards

HPV E7 protein

Oncoprotein that binds to pRb, also causing its degradation.

Signup and view all the flashcards

pRb protein

Retinoblastoma protein, a tumor suppressor that regulates the cell cycle.

Signup and view all the flashcards

Capsid

Protein shell that protects viral nucleic acid and may include viral attachment proteins (VAP).

Signup and view all the flashcards

Proteasomal degradation

Process of breaking down proteins, often targeting damaged ones.

Signup and view all the flashcards

Structural proteins

Proteins that form the capsid and assist with viral genome packaging and attachment.

Signup and view all the flashcards

Koliocyte

Enlarged keratinocyte with a clear halo around the nucleus, indicative of HPV infection.

Signup and view all the flashcards

Non-structural proteins

Proteins necessary for viral replication, assembly and disease facilitation.

Signup and view all the flashcards

Virus-Associated Proteins (VAP)

Proteins on the virus surface that aid in attachment to host cells.

Signup and view all the flashcards

Envelope

Lipid bilayer that functions as an anchoring surface for attachment proteins, aiding in host cell entry.

Signup and view all the flashcards

Common respiratory viruses

Viruses that are significant causes of acute respiratory disease, like influenza and coronaviruses.

Signup and view all the flashcards

Viral transmission

Spread of viral infections typically through respiratory droplets or hand transfer.

Signup and view all the flashcards

Cell tropism

The specificity of a virus to infect certain cell types based on receptors.

Signup and view all the flashcards

Acute respiratory disease (ARD)

Respiratory illnesses primarily caused by viral infections, accounting for high morbidity rates.

Signup and view all the flashcards

Study Notes

MABS Microbiology Course

  • Course covers virology, respiratory, hepatitis, papilloma, polyoma viruses, and human retroviruses.

Course Instructional Objectives

  • MCRO 3.1: Students will describe the taxonomy, structure, and function of coronavirus family viruses. This includes transmission, pathogenesis, stages of viral infection, viral gene expression, viral replication, and effects on the cellular level and/or human immune response.
  • MCRO 3.2: Students will describe the taxonomy, structure, and function of human influenza viruses within the Orthomyxoviridae family. This includes transmission, pathogenesis, stages of viral infection, viral gene expression, viral replication, effects on the cellular level, human immune response, and treatment.
  • MCRO 3.3: Students will describe the taxonomy, structure, and function of human RSV viruses within the Paramyxoviridae family. This includes transmission, pathogenesis, effects on the cellular level, and human immune response.
  • MCRO 3.4: Students will describe the taxonomy, structure, and function of human adenovirus family viruses. This includes transmission, pathogenesis, stages of viral infection, viral gene expression, viral replication, and effects on the cellular level and/or human immune response.
  • MCRO 3.5: Students will describe the taxonomy, structure, and function of retroviruses, especially HIV-1. This includes transmission, pathogenesis, stages of viral infection, viral gene expression, viral replication, effects on the cellular level, and human immune response and/or treatment.
  • MCRO 3.6: Students will describe the taxonomy, structure, and function of human papillomavirus family viruses. This includes transmission, pathogenesis, stages of viral infection, viral gene expression, viral replication, effects on the cellular level, and which types are more or less likely to lead to cancer.
  • MCRO 3.7: Students will describe the taxonomy, structure, and function of human hepatitis viruses, including transmission, pathogenesis, stages of viral infection, and effects on the cellular level and/or human immune response, for specific viruses such as HAV, HBV, and HCV.

Review: Components of a Virus

  • Viruses consist of a nucleic acid (DNA or RNA), capsid, structural proteins, non-structural proteins, and an envelope (in some cases).
  • Nucleic acid encodes information for viral reproduction.
  • Capsid protects the nucleic acid and may contain viral attachment proteins (VAPs).
  • Structural proteins form the capsid and package the genome.
  • Non-structural proteins facilitate replication and assembly of the virus.
  • Envelope serves as an anchoring surface for attachment to host cells and facilitates entry into the host.

Respiratory Viruses

  • Respiratory disease accounts for 75-80% of acute morbidity in the US.
  • Most respiratory illnesses (about 80%) are viral and spread through respiratory droplets and/or hand transfer. Incubation often lasts 1-14 days.
  • Major causes of acute respiratory disease include: parainfluenza, influenza, RSV, coronaviruses (including COVID-19), adenoviruses, rhinoviruses, human metapneumovirus (hMPV), and bocaviruses.

Summary: Coronaviruses

  • Coronaviruses are the largest RNA viruses with a helical nucleocapsid, lipid bilayer envelope, and viral spike glycoproteins.
  • Replication occurs in the cytoplasm.
  • Three novel human coronaviruses cause severe acute respiratory syndrome (SARS-CoV-1, MERS-CoV, and SARS-CoV-2, also known as COVID-19).
  • SARS-CoV-2 is transmitted through respiratory droplets and Spike glycoproteins interact with ACE2 receptors.
  • Molecular and antigen tests detect SARS-CoV-2.

Respiratory Epithelium

  • Upper respiratory tract (above the larynx) has taller epithelial cells with cilia and mucus, to trap and move debris.
  • Lower respiratory tract (below the larynx) has shorter epithelial cells without cilia to promote better diffusion of oxygen and CO2.
  • SARS-CoV-2 enters the respiratory tract at the nasopharyngeal or oropharyngeal region.

Coronavirus General Information

  • Coronaviruses have a positive-sense ssRNA genome, helical capsid, and an envelope with club-shaped proteins.
  • Transmission is via respiratory droplets, and fecal-oral in some cases.
  • The viral attachment protein is E2/spike glycoprotein, with respiratory tract and GI tract epithelium as main tropism.
  • Viruses may undergo significant antigenic changes.
  • Coronaviruses are typically less lethal overall compared to SARS-CoV-1.

Severe Acute Respiratory Syndrome (SARS)

  • Caused by zoonotic coronaviruses and spread via respiratory droplets or feces, urine, and sweat.
  • Infects and kills respiratory epithelial cells.
  • Causes atypical pneumonia with high fever, chills, headache, breathing difficulties, and diarrhea.
  • Mortality rates are influenced by age-related differences in immune responses.

Viral Infection and the Immune System

  • Virus infection triggers a host immune response.
  • Cells become infected and phagocytized to stop replication.
  • Activation of T cells happens to neutralize virus further.

Immune System & Coronaviruses

  • High recruited leukocytes include T cells, monocytes, and neutrophils as part of cell mediated immunity in response to viruses.
  • Viral damage from COVID-19 includes both viral and immune mediator damage in cells and the lungs.
  • Interferon release occurs from natural killer cells and macrophages to combat viral replication.
  • Antibodies to hemagglutinin and neuramidase protect against infection and virus spread.

Summary: Influenza

  • Influenza is an enveloped, pleomorphic, helical virus with single stranded, negative-sense RNA.
  • The three major types are A, B, and C.
  • Virus has two virus-specific glycoproteins: Hemagglutinin (HA), and Neuraminidase (NA).
  • Replication occurs in the nucleus, using viral and host RNA polymerase.

Influenza Virus

  • The family is Orthomyxoviridae, with a linear, ssRNA genome, enveloped, helical capsid.
  • Transmission is via respiratory droplets.
  • Tropism is respiratory epithelium.
  • Major surface glycoproteins include HA that binds to sialic acid and NA that releases the virus from host cells.

Influenza Virus Life Cycle

  • Viral mRNA transcription and genomic RNA replication occurs in the nucleus using viral RNA polymerase and host cell RNA.
  • Newly formed genomes are packaged as virions bud from the plasma membrane.

Influenza Disease

  • Disease symptoms range from mild cold-like illness to severe pneumonia.
  • Complications can include pneumonia (either primary or secondary from a bacterial infection).

Influenza Treatment and Prevention

  • Treatment options include symptomatic care such as antihistamines or acetominaphen, as well as specific viral inhibitors.
  • Prevention typically involves influenza vaccinations that will create HA-specific antibodies to block viral entry.
  • Effective therapies are usually administered during initial onset of infection.

Classification of RNA Viruses

  • A variety of genome and capsid structure combinations exist in RNA viruses.
  • RNA viruses are mainly single-stranded except for Reoviridae.
  • Negative-sense RNA viruses have enveloped and helical capsid structure.
  • Non-enveloped RNA viruses typically have icosahedral capsid structure.

Paramyxoviridae Overview

  • Respiratory syncytial virus (RSV) is a virus in the Paramyxoviridae family.
  • RSV is enveloped, helical, with negative-sense linear RNA.
  • It produces cell fusion in tissue cultures, producing a syncytium.
  • It primarily infects bronchi, bronchioles, and alveoli of the lung.
  • RSV replication and transmission occurs in the cytoplasm and via respiratory route in 4-6 days.
  • Infection causes illnesses such as croup, bronchitis, bronchiolitis, or pneumonia.

Respiratory Syncytial Virus (RSV)

  • Leading cause of fatal respiratory illness in infants and young children.
  • Two serotypes that co-circulate during the RSV season (October-March).
  • Viral attachment proteins include G and F glycoproteins (no hemagglutinin or neuraminidase).
  • Virus tropism limited to respiratory tract; no viremia present.
  • High risk populations include premature infants and the elderly.

Human Papillomavirus (HPV)

  • More than 170 types of HPV infect the human genital tract.
  • HPV is non-enveloped, double-stranded DNA virus of the Papillomaviridae family with an icosahedral outer shell.
  • HPV infection is associated with various diseases, ranging from skin warts to cervical cancer.
  • Some types are associated with low-risk conditions (genital warts, benign cervical dysplasia), while high-risk types (such as HPV-16 and 18) strongly correlate with cervical cancer.
  • HPV infection can include a lytic, latent, and transformation infection state.

Human Papillomavirus (HPV) Transformation

  • HPV E5, E6, and E7 oncoproteins can lead to uncontrolled cell proliferation and cancer.
  • Oncogenes like E5, E6, and E7 can, respectively, stabilize EGFR, degrade p53, and inactivate pRb.
  • HPV can disrupt or cause inactivation of tumor suppressor genes and prevent DNA repair, increasing cell mutation risk and transformation.
  • The result is a higher chance of transformation into cancer.

HPV Diagnosis

  • HPV is diagnosed microscopically to detect hyperkeratosis in koliocytes and using Pap smears.
  • These smears will show abnormalities in cellular and cytologic changes from an abnormal production of keratin.
  • Grading systems may help to stage and classify disease.

Hepatitis Viruses

  • Infections include inflammation of the liver.
  • Most infections are caused by RNA viruses (except Hepatitis-B).
  • Causes can result from viral or non-viral sources, such as alcohol or autoimmune disease.

Hepatitis A Overview

  • Hepatitis A virus (HAV) is in the Picornaviridae family.
  • HAV has positive sense RNA with an icosahedral capsid and is non-enveloped.
  • Infection is acquired through ingestion of contaminated food/shellfish or water.
  • HAV primarily replicates in the intestinal epithelium before spreading to hepatocytes and Kupffer cells.
  • The incubation period is 1 week, lasting at least 10 days before onset of symptoms.
  • HAV infection typically is not chronic.
  • Fecal-oral transmission is the most common route of infection.

Hepatitis C Overview

  • HCV is a Flaviviridae positive-sense ssRNA enveloped virus.
  • Six or seven genotypes exist that differ based on geographical location.
  • HCV has a high mutation rate (results in quasi-species that escape immune response).
  • HCV replication occurs primarily in hepatocytes, and possibly also in B cells.
  • Transmission occurs through blood-to-blood contact (transfusion/organ transplantation) or sexual encounters.
  • The majority of hepatitis C infections are chronic.

Hepatitis B Overview

  • Hepatitis B virus (HBV) is a Hepadnaviridae DNA virus.
  • HBV replicates in the liver through a reverse transcriptase mechanism.
  • HBV infection can result in chronic illnesses such as cirrhosis or hepatocellular carcinoma.
  • HBV is a blood/body fluidborne pathogen from mother to child, and through transfusion/organ transplantation.

Multiple HIV-1 Drug Therapy Options

  • Attachment: uses receptor and co-receptor antagonists to block viral entry.
  • Entry: fusion inhibitors block viral and cellular membrane fusion.
  • Replication: Reverse transcriptase (RT) and integrase inhibitors block viral replication.
  • Assembly/Release: protease inhibitors block viral assembly and release.

HIV-1 Life Cycle

  • HIV-1 gp120 attaches to the CD4 receptor and CCR5 or CXCR4 coreceptor.
  • HIV-1 gp41 protein mediates the fusion of viral and cellular membranes to allow viral entry.
  • Viral RNA and proteins are released into the cell cytoplasm.
  • Reverse transcription makes a DNA copy of the viral RNA, and the DNA is integrated into the host cell genome.
  • Viral mRNA and protein are produced in the nucleus using host enzymes.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Week 3 Virology-Respiratory Hepatitis Retrovirus Papilloma Polyoma Viruses PDF

Description

Test your knowledge on various human pathogenic viruses and their classifications. This quiz covers virus families like Coronaviridae, Orthomyxoviridae, and others, along with their characteristics and functions. Dive deep into the structure and replication processes of these viruses.

More Like This

Adenoviridae, Parvoviridae, and Poxviridae Quiz
10 questions

Adenoviridae, Parvoviridae, and Poxviridae Quiz

CaptivatingDaffodil avatar
CaptivatingDaffodil
Virus and Virus Families Quiz
20 questions

Virus and Virus Families Quiz

LongLastingHelium avatar
LongLastingHelium
Virus Families and Clinical Importance
12 questions

Virus Families and Clinical Importance

WellBehavedEpilogue avatar
WellBehavedEpilogue
Clinically Important RNA Viruses Overview
19 questions

Clinically Important RNA Viruses Overview

LegendaryAlmandine1250 avatar
LegendaryAlmandine1250
Use Quizgecko on...
Browser
Open
Browser
Browser