Podcast Beta
Questions and Answers
A virion is only infectious if fully assembled.
True
Viruses are more resistant to antiseptic than bacteria.
True
The ICTV Family name of Reoviridae is now Sedoreoviridae.
True
Poxviridae is the only DNA virus family that assembles its virion in the cytoplasm.
Signup and view all the answers
There are 8 classes under Baltimore classification.
Signup and view all the answers
What do viruses lack that distinguishes them from living cells?
Signup and view all the answers
What is a complete viral particle called?
Signup and view all the answers
What is the size range of most viruses?
Signup and view all the answers
What do retroviruses uniquely have in terms of their genetic material?
Signup and view all the answers
What process refers to agents that disrupt viral structure or function?
Signup and view all the answers
What kind of damage does UV light cause to the viral genome?
Signup and view all the answers
Study Notes
Virology: Viruses are Obligate Intracellular Parasites
- Viruses are acellular and do not have organelles such as ribosomes or mitochondria.
- They require a host cell to replicate and are considered obligate intracellular parasites.
- Viruses lack the capacity for self-replication outside of a living host cell.
Reproduction of Viruses
- Viruses must follow a specific process to reproduce:
- Attachment: The virus attaches to a susceptible host cell.
- Entry: The virus enters the cell or injects its genetic material.
- Replication: The virus uses the host's machinery to replicate its genome and produce viral proteins .
- Assembly: The virus assembles new viral particles.
- Release: The newly formed virions are released from the host cell, often damaging or killing it, to infect other cells.
Structure of the Virion
- The virion is the entire infectious unit or viral particle. It consists of:
- Genome: DNA or RNA
- Capsid: A protein shell that encases and protects the viral genome.
- Capsomere: The protein subunits that make up the capsid. They play a role in recognizing and binding to the host cell during infection.
- Envelope: Some viruses have an envelope composed of lipids and proteins that helps the virus enter host cells.
Virus Size & Shape
- Virus size ranges between 20-200 nanometers.
- Examples:
- Picornaviruses (e.g., Poliovirus): 20–30 nm in diameter.
- Poxviruses (e.g., Variola virus): 200 nm in diameter.
Virus Genome: Haploid vs. Diploid
- Most viruses contain a single copy of their genetic material and are considered haploid.
- Retroviruses are an exception and have a diploid genome.
Resistance and Inactivation of Viruses
- Viruses are more resistant to antiseptics than bacteria.
- Viruses can survive for long periods under harsh conditions, such as when freeze-dried at -70°C.
-
Inactivation of viruses refers to disrupting their structure or function.
- UV and X-ray can inactivate viruses by damaging their DNA or RNA. UV light causes damage by forming pyrimidine dimers, while X-rays cause breaks in the viral genetic material.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz focuses on key concepts in virology, particularly the nature of viruses as obligate intracellular parasites. It covers their reproduction process and structure, providing insights into how viruses attach, enter, replicate, and release from host cells. Test your knowledge of viral biology and mechanisms!
