Podcast
Questions and Answers
What is a distinguishing feature of all viruses compared to bacteria?
What is a distinguishing feature of all viruses compared to bacteria?
- Ability to reproduce independently
- Encased in a protein shell called a capsid (correct)
- Single circular DNA chromosome
- Presence of membrane-bound organelles
Which type of virus is HIV classified as based on its nucleic acid?
Which type of virus is HIV classified as based on its nucleic acid?
- Single-stranded DNA
- Double-stranded RNA
- Single-stranded RNA (correct)
- Double-stranded DNA
Which of the following is NOT a feature of bacteria?
Which of the following is NOT a feature of bacteria?
- Presence of chlorophyll (correct)
- Ancient life form
- Lack of membrane-bound organelles
- Single circular DNA chromosome
What type of symmetry does the influenza virus exhibit?
What type of symmetry does the influenza virus exhibit?
What is the primary tropism of the Hepatitis B virus?
What is the primary tropism of the Hepatitis B virus?
Which virus is characterized by its ability to mutate more rapidly?
Which virus is characterized by its ability to mutate more rapidly?
Which of the following viruses causes cold sores?
Which of the following viruses causes cold sores?
What is the classification of Varicella Zoster Virus based on its nucleic acid?
What is the classification of Varicella Zoster Virus based on its nucleic acid?
Which type of cell does HIV primarily target?
Which type of cell does HIV primarily target?
Which statement about gram-negative bacteria is true?
Which statement about gram-negative bacteria is true?
Which virus is primarily associated with the persistence of infections without killing host cells?
Which virus is primarily associated with the persistence of infections without killing host cells?
What best describes viral latency?
What best describes viral latency?
What is the first step in the viral replication cycle?
What is the first step in the viral replication cycle?
Which type of tropism is demonstrated by the Hepatitis B virus?
Which type of tropism is demonstrated by the Hepatitis B virus?
What is a key feature that distinguishes prions from viruses?
What is a key feature that distinguishes prions from viruses?
Which of the following infections could be caused by a prion?
Which of the following infections could be caused by a prion?
What process describes how new virions are released from an infected host cell?
What process describes how new virions are released from an infected host cell?
What type of virus is commonly associated with oropharyngeal cancers?
What type of virus is commonly associated with oropharyngeal cancers?
Viral persistence is characterized by which of the following?
Viral persistence is characterized by which of the following?
What defines the mechanism of adsorption in viral replication?
What defines the mechanism of adsorption in viral replication?
Flashcards
Bacteria: Key features
Bacteria: Key features
Single-celled organisms lacking chlorophyll, with a single circular DNA chromosome and no membrane-bound organelles.
Gram staining
Gram staining
A technique used to classify bacteria based on their cell wall structure, dividing them into Gram-positive and Gram-negative groups.
Viral Capsid
Viral Capsid
Protein shell that encases the viral genome, protecting and delivering the genetic material.
Viral Genome
Viral Genome
Signup and view all the flashcards
Viral Envelope
Viral Envelope
Signup and view all the flashcards
Nucleocapsid
Nucleocapsid
Signup and view all the flashcards
Viral Symmetry
Viral Symmetry
Signup and view all the flashcards
Viral Nucleic Acid Classification
Viral Nucleic Acid Classification
Signup and view all the flashcards
HIV: Structure and Classification
HIV: Structure and Classification
Signup and view all the flashcards
Hepatitis B Virus: Structure and Classification
Hepatitis B Virus: Structure and Classification
Signup and view all the flashcards
Viral Tropism
Viral Tropism
Signup and view all the flashcards
Cellular Tropism
Cellular Tropism
Signup and view all the flashcards
Tissue Tropism
Tissue Tropism
Signup and view all the flashcards
Host Tropism
Host Tropism
Signup and view all the flashcards
Viral Replication Cycle
Viral Replication Cycle
Signup and view all the flashcards
Viral Persistence
Viral Persistence
Signup and view all the flashcards
Viral Latency
Viral Latency
Signup and view all the flashcards
Prions
Prions
Signup and view all the flashcards
Prion Diseases
Prion Diseases
Signup and view all the flashcards
Key Features of Prions
Key Features of Prions
Signup and view all the flashcards
Study Notes
Bacterial Features
- Bacteria are single-celled microorganisms.
- They are ancient life forms.
- Basic cellular functions are similar to other living cells.
- Lack chlorophyll.
- Typically have a single, circular DNA chromosome within the cytoplasm.
- Lack membrane-bound organelles.
Gram Staining
- Gram staining classifies bacteria into two groups: Gram-positive and Gram-negative.
Viral Structure and Classification
-
Structure:
- Capsid: Protein coat enclosing the viral genome.
- Viral Genome: DNA or RNA (never both).
- Envelope: Some viruses have a lipid membrane surrounding the capsid.
- Nucleocapsid: Combined capsid and genome.
- Other Viral Proteins: Involved in replication.
-
Classification:
- Symmetry: Icosahedral, filamentous, or complex.
- Nucleic Acid: DNA (dsDNA or ssDNA) or RNA (ssRNA or dsRNA). RNA viruses mutate more frequently.
Specific Virus Features
-
HIV:
- Symmetry: Icosahedral.
- Nucleic Acid: ssRNA, retrovirus.
- Tropism: Targets CD4+ T-cells.
-
Hepatitis B Virus (HBV):
- Symmetry: Icosahedral.
- Nucleic Acid: dsDNA.
- Tropism: Infects liver cells.
-
Varicella Zoster Virus (VZV):
- Symmetry: Icosahedral.
- Nucleic Acid: dsDNA.
- Tropism: Skin and nerve cells (chickenpox/shingles).
-
Herpes Simplex Virus (HSV):
- Symmetry: Icosahedral.
- Nucleic Acid: dsDNA.
- Tropism: Skin, mucous membranes, nerve cells (cold sores/genital herpes).
-
Influenza Virus:
- Symmetry: Filamentous or spherical.
- Nucleic Acid: ssRNA.
- Tropism: Respiratory tract cells.
Dentally Relevant Viruses
- Herpes Simplex Virus (HSV-1): Oral herpes (cold sores).
- Varicella Zoster Virus (VZV): Chickenpox/shingles (can affect oral tissues).
- HIV: Immunocompromised patients susceptible to oral infections (e.g., candidiasis, Kaposi's sarcoma).
- Human Papillomavirus (HPV): Linked to oral cancers.
- Hepatitis B Virus (HBV): Risk of transmission during dental procedures.
Viral Tropism
- Viral tropism: Ability to infect specific cells, tissues, or hosts.
- Cellular tropism: Virus infects specific cell types.
- Tissue tropism: Virus preference for particular tissues.
- Host tropism: Viruses infecting specific species.
Viral Replication
- Adsorption: Virus attaches to host cell receptors.
- Penetration: Virus enters host cell.
- Uncoating/Eclipse Phase: Viral genome is released.
- Transcription: Viral genome produces mRNA.
- Synthesis of Components: Viral proteins and genomes produced.
- Assembly: Viral components assemble into new virions.
- Release: Virions released (lysis or budding).
Viral Persistence and Latency
- Viral Persistence: Virus presence without immune clearance. Can include productive phases.
- Examples: HIV, Epstein-Barr virus, Hepatitis B virus.
- Viral Latency: Dormant virus in host cells. Replication triggered by external factors (stress, immunity suppression).
- Examples: Herpes Simplex Virus (HSV), Varicella-Zoster Virus (VZV).
Prions
- Prions: Infectious misfolded proteins causing other proteins to misfold.
- Key Feature: Lack nucleic acids, resistant to denaturation.
- Diseases: Neurodegenerative like Creutzfeldt-Jakob Disease (CJD) and Bovine Spongiform Encephalopathy (BSE).
- Relevance: Fatal; difficult to sterilize against.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
