Recent

  • Show all results for ""
Cell Death Mechanisms: Necrosis vs Apoptosis vs Autophagy
43 Questions
1 Views

Cell Death Mechanisms: Necrosis vs Apoptosis vs Autophagy

Created by
@StateOfTheArtViolet

Questions and Answers

What is the primary characteristic that distinguishes necrosis from apoptosis?

  • Necrosis triggers inflammation and tissue damage. (correct)
  • Necrosis is a regulated process.
  • Apoptosis involves cell swelling.
  • Apoptosis occurs due to external factors only.

    • Which pathway is initiated by internal cellular damage during apoptosis?

  • Necrotic pathway
  • Extrinsic pathway
  • Intrinsic pathway (correct)
  • Caspase pathway

    • During which process do cells typically undergo chromatin condensation?

  • Apoptosis (correct)
  • Autophagy
  • Necrosis
  • Inflammatory response

    • What is a consequence of necrosis for surrounding tissues?

    <p>It leads to inflammatory response and tissue damage.</p> Signup and view all the answers

    What initiates the extrinsic pathway of apoptosis?

    <p>Binding of death ligands to surface receptors</p> Signup and view all the answers

    Which event is most closely associated with necrosis?

    <p>Cell membrane rupture and release of contents</p> Signup and view all the answers

    What is a feature of apoptosis that differentiates it from other forms of cell death?

    <p>It can be triggered by intrinsic factors.</p> Signup and view all the answers

    Which factor is NOT typically associated with necrosis?

    <p>Intracellular signaling</p> Signup and view all the answers

    What is a key characteristic that differentiates apoptosis from necrosis?

    <p>Apoptosis is a controlled process with non-inflammatory outcomes.</p> Signup and view all the answers

    How does autophagy contribute to cellular health during stress?

    <p>By degrading damaged organelles and proteins.</p> Signup and view all the answers

    Which of the following processes does NOT involve caspases?

    <p>Both B and C</p> Signup and view all the answers

    What occurs when autophagy is excessively activated?

    <p>Induction of autophagic cell death</p> Signup and view all the answers

    What is the primary role of caspases in apoptosis?

    <p>To degrade cellular components</p> Signup and view all the answers

    Under what condition does autophagy primarily operate?

    <p>Under conditions of nutrient deprivation.</p> Signup and view all the answers

    What happens to the apoptotic bodies formed during apoptosis?

    <p>They are phagocytosed by nearby cells.</p> Signup and view all the answers

    Which process is primarily responsible for cell rupture and inflammation?

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

    What can be said about apoptosis concerning energy requirement?

    <p>It requires energy and is regulated.</p> Signup and view all the answers

    Which statement best describes the relationship between autophagy and apoptosis?

    <p>Autophagy can delay apoptosis by repairing the cell.</p> Signup and view all the answers

    What is the main difference between apoptosis and necrosis?

    <p>Apoptosis is an energy-dependent process that prevents inflammation, while necrosis is uncontrolled and causes inflammation.</p> Signup and view all the answers

    During embryonic development, what role does apoptosis play in shaping tissues?

    <p>It eliminates excessive or mispositioned cells, facilitating the formation of structures.</p> Signup and view all the answers

    Which of the following best describes ‘apoptotic bodies’?

    <p>They are membrane-bound vesicles containing cell fragments formed during apoptosis.</p> Signup and view all the answers

    In the developing nervous system, what is the primary function of apoptosis?

    <p>To eliminate excess neurons and ensure proper neural connectivity.</p> Signup and view all the answers

    What purpose does autophagy serve in cellular homeostasis?

    <p>It recycles cellular components and removes damaged organelles.</p> Signup and view all the answers

    What is the role of procaspase-3 in apoptosis?

    <p>It is cleaved to form caspase-3.</p> Signup and view all the answers

    What initiates the extrinsic pathway of apoptosis?

    <p>Cleavage of procaspase-8 by death receptors.</p> Signup and view all the answers

    Which protein is involved in the formation of the apoptosome?

    <p>Apaf-1</p> Signup and view all the answers

    Which process does Bax primarily influence during apoptosis?

    <p>Releasing cytochrome c from mitochondria.</p> Signup and view all the answers

    What impact does the mitochondrial permeability transition pore (MPTP) have in cell death?

    <p>It forms pores leading to apoptosis or necrosis.</p> Signup and view all the answers

    What is the primary function of cyclophilin D?

    <p>To regulate the mitochondrial permeability transition pore.</p> Signup and view all the answers

    Which statement accurately describes procaspase-9?

    <p>It is activated by cytochrome c in the intrinsic pathway.</p> Signup and view all the answers

    Which component is NOT part of the intrinsic apoptosis pathway?

    <p>Death receptors</p> Signup and view all the answers

    What is a direct consequence of cytochrome c release into the cytosol?

    <p>Formation of the apoptosome and activation of procaspase-9.</p> Signup and view all the answers

    How does the activity of caspase-3 contribute to the execution phase of apoptosis?

    <p>By cleaving various cellular substrates.</p> Signup and view all the answers

    Which caspase initiates the extrinsic pathway of apoptosis?

    <p>Caspase-8</p> Signup and view all the answers

    What is the role of cytochrome c in the intrinsic pathway of apoptosis?

    <p>Forms the apoptosome with Apaf-1</p> Signup and view all the answers

    What is the primary action of caspase-activated DNase (CAD) during apoptosis?

    <p>To cleave DNA at internucleosomal regions</p> Signup and view all the answers

    What differentiates apoptosis from necrosis with regard to cellular contents?

    <p>Necrosis releases contents in a disorganized manner</p> Signup and view all the answers

    Which pro-apoptotic proteins are primarily responsible for mitochondrial outer membrane permeabilization (MOMP)?

    <p>Bax and Bak</p> Signup and view all the answers

    In which phase of apoptosis are executioner caspases activated?

    <p>Execution Phase</p> Signup and view all the answers

    What occurs during chromatin condensation in apoptotic cells?

    <p>DNA is fragmented into nucleosomal units</p> Signup and view all the answers

    What is the result of the release of Smac/DIABLO from the mitochondria during apoptosis?

    <p>Neutralization of inhibitors of apoptosis proteins (IAPs)</p> Signup and view all the answers

    Which of the following describes the timeline of the apoptosis process?

    <p>It can occur within hours and consists of distinct stages</p> Signup and view all the answers

    What triggers the activation of CAD in apoptosis?

    <p>Caspase-3</p> Signup and view all the answers

    Study Notes

    Necrosis

    • Uncontrolled form of cell death caused by injury, infection, or extreme stress.
    • Characterized by cell swelling, membrane rupture, and inflammatory response.
    • Involves release of intracellular contents into extracellular space, causing tissue damage.
    • Commonly results from ischemia, toxins, or trauma.
    • Key features include being passive, external triggers, and harmful outcomes for surrounding tissue.

    Apoptosis

    • Programmed cell death, highly regulated, allowing removal of damaged or unnecessary cells without inflammation.
    • Initiated by intrinsic (internal damage) or extrinsic (external signals) pathways.
    • Involves controlled processes: cell shrinkage, chromatin condensation, DNA fragmentation, and formation of apoptotic bodies.
    • Intrinsic pathway: Activated by DNA damage; includes mitochondrial outer membrane permeabilization and caspase-9 activation.
    • Extrinsic pathway: Triggered by death ligands binding to receptors; activates caspase-8.
    • Key features include energy dependence, caspase involvement, and non-inflammatory removal of cells.

    Autophagy

    • Survival mechanism where cells degrade and recycle damaged organelles or proteins to maintain homeostasis.
    • Not a form of cell death; can delay apoptosis by promoting repair under stress.
    • Begins with autophagosome formation, leading to lysosomal degradation of engulfed components.
    • Does not involve caspases or result in DNA fragmentation.
    • Aids in nutrient provision during stressful conditions without causing inflammation.

    Comparative Summary

    • Necrosis is uncontrolled and harmful, leading to tissue damage and inflammation, while apoptosis is a clean, regulated process that avoids inflammation.
    • Autophagy promotes survival and repair through recycling of damaged components but is not inherently lethal like necrosis or apoptosis.

    Caspase Pathways

    • Procaspase-3 and Caspase-3 play critical roles in the execution phase of apoptosis.
    • Procaspase-8 activates in the extrinsic pathway upon death receptor engagement, initiating the apoptotic cascade.
    • Procaspase-9 is activated in the intrinsic pathway via the apoptosome, which begins the cascade.

    Mitochondria's Role in Apoptosis

    • Central to the intrinsic pathway, releasing cytochrome c which forms the apoptosome and activates caspase-9.
    • Involved in releasing other pro-apoptotic factors that promote cell death.

    DNA Fragmentation in Apoptosis

    • Activation of endonucleases (CAD) results in DNA fragmentation; chromatin condenses, leading to a characteristic pattern.
    • Controlled process in apoptosis, contrasting with necrosis where DNA is released in a chaotic manner causing inflammation.

    Stages of Apoptosis

    • Initiation phase involves activation of initiator caspases.
    • Execution phase consists of executioner caspases cleaving cellular proteins, leading to cell shrinkage.
    • Formation of apoptotic bodies occurs, which are later phagocytosed to prevent inflammation.

    Role in Development and Function

    • Apoptosis shapes tissues during embryonic development, removing excess or misplaced cells (e.g., separation of fingers).
    • Essential in neuronal development, eliminating excess neurons to ensure proper connections.
    • Supports the maturation of organisms by removing unnecessary structures during growth.

    Studying That Suits You

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

    Quiz Team

    Description

    This quiz compares and contrasts necrosis, apoptosis, and autophagy, highlighting the main steps and characteristics of each process. Learn about the triggers and consequences of these distinct forms of cell death or survival. Test your understanding of these critical biological concepts.

    More Quizzes Like This

    Understanding Cell Death Process
    10 questions

    Understanding Cell Death Process

    EvocativeMossAgate9021 avatar
    EvocativeMossAgate9021
    Cell Death: Necrosis and Apoptosis
    36 questions

    Cell Death: Necrosis and Apoptosis

    JovialCyclops avatar
    JovialCyclops
    Cell Death: Apoptosis and Necrosis
    30 questions

    Cell Death: Apoptosis and Necrosis

    ResourcefulPegasus avatar
    ResourcefulPegasus
    Cell Death Mechanisms: Necrosis, Apoptosis, Autophagy
    9 questions

    Cell Death Mechanisms: Necrosis, Apoptosis, Autophagy

    StateOfTheArtViolet avatar
    StateOfTheArtViolet
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser