Endocytosis and Nanomaterials Quiz
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Questions and Answers

Which of the following is NOT a type of pinocytosis?

  • Mitochondria-mediated endocytosis (correct)
  • Clathrin-mediated endocytosis
  • Caveolin-mediated endocytosis
  • Macropinocytosis

    • What is the size range of nanomaterials that are likely to be swallowed via phagocytosis?

  • Between 750 and 1000 nm
  • Between 1000 and 1500 nm
  • Less than 750 nm (correct)
  • Greater than 1500 nm

    • Which type of carbon nanotubes induced significantly cytotoxicity, genotoxicity, and potent cellular oxidative stress?

  • Both Fe-rich and Fe-free CNTs
  • Fe-free CNTs
  • The text does not mention any specific type of carbon nanotubes.
  • Fe-rich CNTs (correct)

    • Which of the following is a possible mechanism of membrane damage caused by cationic nanomaterials?

    <p>Formation of nano-holes in cell membranes</p> Signup and view all the answers

    What is a widely observed end point for nanotoxicity?

    <p>Oxidative damage</p> Signup and view all the answers

    Which signaling pathways are most commonly disturbed by nanomaterials?

    <p>MAPKs pathways</p> Signup and view all the answers

    What happens when nanomaterials are functionalized with hydrophobic or amphiphilic chains?

    <p>They can damage the membrane by diffusion effects</p> Signup and view all the answers

    What is the main difference between phagocytosis and pinocytosis in terms of the size of nanomaterials they can internalize?

    <p>Phagocytosis and pinocytosis can internalize NMs of the same size range</p> Signup and view all the answers

    Which type of endocytosis is associated with the formation of invaginations coated with clathrin?

    <p>Clathrin-mediated endocytosis</p> Signup and view all the answers

    Which type of carbon nanotubes induced cytotoxicity, genotoxicity, and cellular oxidative stress in alveolar macrophages?

    <p>Fe-rich CNTs</p> Signup and view all the answers

    Which type of charge is more toxic for nanomaterials in blood circulation?

    <p>Positively charged</p> Signup and view all the answers

    What is the possible mechanism of membrane damage caused by cationic nanomaterials?

    <p>Production of nanosized pores in the cell membrane of red blood cells</p> Signup and view all the answers

    Which signaling pathways are most commonly disturbed by nanomaterials?

    <p>MAPKs pathways</p> Signup and view all the answers

    What happens to the cell membrane when nanomaterials are functionalized with hydrophobic or amphiphilic chains?

    <p>The membrane becomes more permeable</p> Signup and view all the answers

    Which of the following is NOT a type of endocytosis?

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

    Which type of nanomaterial uptake is observed among nearly all cells?

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

    What is the main difference between Fe-rich and Fe-free carbon nanotubes in terms of their toxicity to alveolar macrophages?

    <p>Fe-rich CNTs are more toxic than Fe-free CNTs</p> Signup and view all the answers

    Which of the following is a possible reason why positively charged nanomaterials are more toxic in blood circulation?

    <p>They induce hemolysis and platelet deposition</p> Signup and view all the answers

    What is the possible mechanism of membrane damage caused by cationic nanomaterials?

    <p>They produce nanosized pores in cell membranes</p> Signup and view all the answers

    Why are positively charged nanomaterials more favorable to the negatively charged cell membrane?

    <p>Because of the electrostatic attraction between opposite charges</p> Signup and view all the answers

    Macropinocytosis is a type of clathrin-mediated endocytosis.

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

    Direct penetration is the only pathway for very small nanoparticles to enter the cell.

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

    The toxicity of nanomaterials is mainly caused by their chemical components rather than impurities.

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

    Positively charged nanomaterials are less toxic than neutralized or negatively charged ones in blood circulation.

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

    The formation of nano-holes in cell membranes caused by positively charged NMs can lead to colloid-osmotic lysis.

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

    NMs functionalized with neutralizing chemical groups have been shown to induce membrane holes and cytotoxicity in some studies.

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

    Nanomaterials can cut cell membranes to induce toxicity, but only CNT aggregates have been shown to be toxic to bacteria.

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

    Which of the following is a definition of prooxidants?

    <p>Chemicals that induce oxidative stress by formation of ROS or by inhibiting the antioxidant system</p> Signup and view all the answers

    Which of the following is NOT a reactive oxygen species (ROS)?

    <p>Nitrogen dioxide (NO2)</p> Signup and view all the answers

    Which of the following is an example of an antioxidant mechanism found in the biological system?

    <p>Superoxide dismutase (SOD)</p> Signup and view all the answers

    Which enzyme system is the main source of ROS in the vasculature?

    <p>NADPH oxidases</p> Signup and view all the answers

    Which organelle contains numerous enzymes that help to catalyze redox reactions?

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

    What is the possible source of exogenous oxidants that could perturb the intracellular oxidative state?

    <p>Extracellular inflammatory cytokines</p> Signup and view all the answers

    What is the possible effect of oxidative stress at the cellular level?

    <p>Cell death</p> Signup and view all the answers

    What is the most biologically active form of vitamin E and how does it exhibit antioxidant ability?

    <p>α-tocopherol, which is lipid-soluble and can react with unpaired electrons from free radicals</p> Signup and view all the answers

    What is the role of controlled ROS release in the antibacterial or anticancer properties of NPs?

    <p>ROS release can selectively target bacteria or cancer cells, leading to their destruction</p> Signup and view all the answers

    What is the primary reason that ascorbic acid exhibits a broad spectrum of antioxidant activities?

    <p>It can react with various ROS and free radical species</p> Signup and view all the answers

    What is the function of tumor suppressor p53 in response to oxidative stress?

    <p>p53 promotes antioxidative activity to counteract the stress and maintains cell viability at high levels of oxidative stress</p> Signup and view all the answers

    What are the two categories of antioxidative mechanisms that cells use to counteract oxidative stress?

    <p>Enzymatic systems and nonenzymatic systems</p> Signup and view all the answers

    What is the function of catalase in response to oxidative stress?

    <p>Catalase catalyzes the decomposition of H2O2 to water and oxygen, thereby lowering the risk of .OH formation</p> Signup and view all the answers

    What is the function of ferritin in response to oxidative stress?

    <p>Ferritin stores and controls the release of iron ions, and contributes to the scavenging of free iron and reduce overall iron-induced redox activity</p> Signup and view all the answers

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