Skip to main content
뒤로

Viruses - Anatomy & Physiology Micro Lecture 3

컨트롤 버튼이 '내비게이션' 모드로 변경되었습니다.
1/21

이 집합의 용어 (21)

  • What are the general characteristics of viruses?
    Miniscule size (10-500nm), acellular (no organelles, membrane, ribosomes), obligate parasites, small genome (DNA or RNA), no metabolism, do not grow or divide, hijack host cell machinery to reproduce.
  • What is a virion?
    The extracellular state of a virus consisting of a protein coat (capsid) surrounding the nucleic acid genome; some have a phospholipid envelope, others are naked.
  • What determines viral specificity or host range?
    Viral surface proteins target complementary host cell proteins (receptors), determining tissue tropism and host range.
  • What are capsomeres?
    Protein subunits that make up the core capsid structure of a virus.
  • Name the common capsid shapes of viruses.
    Helical (repeating homopolymer protein) and polyhedral (commonly icosahedral, 20-sided).
  • What is a bacteriophage?
    A virus that infects bacteria, often with complex capsid structures and tail fibers for bacterial cell wall penetration.
  • List the genome types used to classify viruses.
    dsDNA, ssDNA, dsRNA, +ssRNA (sense), and -ssRNA (antisense).
  • What is the lytic cycle in viral replication?
    A viral replication cycle resulting in host cell lysis and death, involving attachment, penetration, biosynthesis, maturation, and release.
  • Describe the attachment stage of the lytic cycle.
    Viral proteins recognize and bind to specific host cell receptor proteins, determining host specificity.
  • What happens during the penetration stage of the lytic cycle?
    The virus injects its genome (and sometimes enzymes) into the host cytoplasm; viral enzymes may degrade host DNA.
  • What occurs during biosynthesis in the viral lytic cycle?
    The virus hijacks host enzymes to replicate viral genomes and produce viral proteins like capsomeres and enzymes.
  • What is the maturation stage in viral replication?
    Assembly of viral components into new virions; sometimes the genome is packaged into the capsid.
  • How are new virions released in the lytic cycle?
    Host cell membrane or wall is degraded by enzymes, causing cell lysis and release of virions.
  • What is the lysogenic cycle?
    A viral replication cycle where viral DNA integrates into the host genome as a prophage, allowing host survival and viral dormancy.
  • What triggers induction in the lysogenic cycle?
    Stress conditions cause the prophage to excise from the host genome and enter the lytic cycle.
  • What is lysogenic conversion?
    Prophage genes alter host cell properties, such as resistance to other phages and increased virulence (e.g., toxin production).
  • How do animal viruses differ in their life cycle from bacteriophages?
    Similar life cycle but with alternative penetration, biosynthesis, and release methods; attachment via spike proteins to host receptors.
  • Where do dsDNA and RNA animal viruses replicate?
    dsDNA viruses often replicate in the nucleus; RNA viruses usually replicate in the cytoplasm using viral RNA polymerase.
  • How are enveloped animal viruses released?
    By budding through the host cell membrane, allowing slow, steady virus shedding without killing the host cell.
  • What is a retrovirus and how does it replicate?
    +ssRNA virus that uses reverse transcriptase to make a dsDNA copy, which integrates into the host genome as a provirus.
  • What are latent viral infections?
    Viruses remain dormant for long periods without integrating into the host genome, reactivating later to cause acute or chronic infections.