Cell Biology: Chromatin and Genome Structure
21 Questions
1 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

Which statement is true regarding the smooth endoplasmic reticulum?

  • It is primarily involved in the degradation of proteins.
  • It functions mainly in lipid synthesis. (correct)
  • It synthesizes glycoproteins.
  • It contains ribosomes for protein synthesis.
  • What is the primary consequence of the absence of hexosaminidase A in Tay-Sachs disease?

  • Increased levels of beta-glucuronidase.
  • Accumulation of gangliosides. (correct)
  • Decreased production of glycosaminoglycans.
  • Improved lysosomal function.
  • Which of the following best describes peroxisomes?

  • They lack a membrane structure.
  • They primarily synthesize carbohydrates.
  • They are involved in protein biosynthesis.
  • They are called microbodies. (correct)
  • In mucopolysaccharidosis, what is typically absent?

    <p>Beta-glucuronidase.</p> Signup and view all the answers

    Which type of protein is embedded within the cell membrane?

    <p>Integral proteins.</p> Signup and view all the answers

    What is the primary role of adaptor proteins in phagocytosis?

    <p>They selectively recruit clarithin and bind to cargo receptors.</p> Signup and view all the answers

    What is the primary function of membrane proteins as adhesion molecules?

    <p>Facilitating communication with other cells.</p> Signup and view all the answers

    What is the function of clarithin during the process of phagocytosis?

    <p>It bends the membrane to create clarithin-coated pits.</p> Signup and view all the answers

    What role does dynamin play in phagocytosis?

    <p>It is responsible for the final scission of the vesicle from the plasma membrane.</p> Signup and view all the answers

    Lysosomal storage diseases result from a deficit in which of the following?

    <p>Specific hydrolytic enzymes.</p> Signup and view all the answers

    What does the crystalline core of peroxisomes primarily contain?

    <p>Urate oxidase.</p> Signup and view all the answers

    What compartment plays a critical role in determining the fate of internalized molecules during phagocytosis?

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

    Which of the following statements regarding lysosomes is correct?

    <p>Lysosomes contain enzymes that degrade internalized materials.</p> Signup and view all the answers

    What is the primary characteristic of heterochromatin?

    <p>It is densely packed and generally not expressed.</p> Signup and view all the answers

    Which component is essential for the structure of nucleosomes?

    <p>A segment of DNA.</p> Signup and view all the answers

    What is the primary function of the Golgi apparatus?

    <p>Modification and packaging of proteins.</p> Signup and view all the answers

    Which statement accurately describes the rough endoplasmic reticulum?

    <p>It contains ribosomes and synthesizes proteins.</p> Signup and view all the answers

    How do lysosomal enzymes function optimally?

    <p>In an acidic environment with a pH of around 5.</p> Signup and view all the answers

    Which two subunits make up ribosomes in eukaryotes?

    <p>60s and 40s.</p> Signup and view all the answers

    Which of the following is NOT typically associated with lysosomal function?

    <p>Synthesis of carbohydrates.</p> Signup and view all the answers

    What distinguishes lysosomal storage diseases?

    <p>Accumulation of toxic substances due to enzyme deficiency.</p> Signup and view all the answers

    Study Notes

    Smooth Endoplasmic Reticulum

    • Lacks ribosomes, distinguishing it from rough ER, and primarily involved in lipid synthesis.
    • Higher pH of cytosol can inactivate certain contents, a safety measure for cell function.

    Lysosomal Storage Diseases

    • Tay-Sachs Disease

      • Caused by the absence of hexosaminidase A.
      • Results in the accumulation of gangliosides, affecting neurological function.
    • Mucopolysaccharidosis

      • Caused by absence of beta-glucuronidase.
      • Leads to the accumulation of glycosaminoglycans, impacting cellular processes.

    Membrane Proteins

    • Composed of proteins (55%) with types including:

      • Integral Proteins

        • Embedded in or traverse the membrane, forming structural channels or pores.
      • Peripheral Proteins

        • Located on either side of the membrane; function as enzymes or assist in transport processes.
    • Functions of Membrane Proteins

      • Acts as adhesion molecules for cell communication.
      • Integral proteins serve as receptors with a high affinity for specific ligands, initiating cell signaling.
      • Ligands aggregate and cause invagination, leading to the formation of endosomes and vesicles.

    Lysosomes

    • Known as the cell's digestive system, containing hydrolytic enzymes collectively called acid hydrolases.
    • Operate efficiently within an acidic environment, crucial for breaking down biomolecules.
    • Plasma membrane is a phospholipid bilayer derived from the Golgi apparatus.

    Phagocytosis

    • Refers to the process of "cell eating."
      • Involves pseudopodia formation, enclosing molecules in vacuoles, and fusing membranes to form phagosomes.
      • Endosomes direct the fate of internalized molecules for recycling or degradation.

    Clathrin-Mediated Endocytosis

    • Adaptor proteins recruit clathrin, helping select cargo for endocytosis.
    • Clathrin forms coated pits on the membrane, which bud off to create vesicles.
    • Dynamin facilitates the final detachment of vesicles from the plasma membrane.

    Chromatin and Nucleus

    • Heterochromatin

      • Densely packed and typically inactive in gene expression.
    • Chromosomes

      • Highly organized chromatin structure, condensed during cell division.
    • Nucleosomes

      • The fundamental unit of chromatin, containing segments of DNA.

    Genome and Genes

    • Genome encompasses all genetic material, including coding and non-coding regions.
    • Genes are specific DNA sequences that summon the production of proteins.

    Endoplasmic Reticulum

    • Acts as the cell's factory with two distinct regions:
      • Rough Endoplasmic Reticulum (RER)

        • Characterized by ribosomes, focuses on protein synthesis.
        • Ribosomes consist of ribosomal RNA (rRNA) and proteins, specifically the 60s and 40s subunits.
      • Lipid Synthesis

        • Smooth ER involved in the biosynthesis of lipids and metabolic processes.

    Acidic Environment of Lysosomes

    • Optimal pH for acid hydrolases is around 5, while the cytosol's pH hovers around 7.4, emphasizing the importance of compartmentalization in cellular functions.

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Medical Histology PDF

    Description

    This quiz covers key concepts related to the structure and organization of chromatin, including heterochromatin, nucleosomes, and chromosomes. It also explores the structure of the genome and the plasma membrane of organelles such as lysosomes. Test your understanding of these fundamental cellular components.

    More Like This

    Cell Structure: Chromatin and Organelles
    34 questions
    MBG lecture 2
    42 questions

    MBG lecture 2

    StateOfTheArtViolet avatar
    StateOfTheArtViolet
    Module Génétique 2ème année
    18 questions

    Module Génétique 2ème année

    ResilientSocialRealism avatar
    ResilientSocialRealism
    Use Quizgecko on...
    Browser
    Browser