LEC 2

    Cards (37)

    • What is the maximum magnification of transmitted light microscopy?
      1000 times
    • What is the resolution of transmitted light microscopy?
      0.2 um
    • What type of specimen preparation is required for transmitted light microscopy?
      Prepared in a way that allows light to pass through it
    • What type of information does transmitted light microscopy provide about structures?
      Shows shape of structures, but doesn't give molecular information
    • Is transmitted light microscopy suitable for live cells?
      Yes
    • What is the principle behind fluorescence light microscopy?
      absorb light at one wavelength and emit it at a longer wavelength.
    • What is the role of an excitation filter in fluorescence light microscopy?
      is used to select the wavelength of light that excites the fluorescent dye.
    • What does an emission filter do in fluorescence light microscopy?
      is used to allow only the emitted light from the sample to reach the observer's eye.
    • How are fluorescent dyes used to label specific cellular components?
      Some dyes bind to specific cellular components like DNA, mitochondria, or lysosomes.
    • In fluorescence microscopy, how are dyes coupled to antibodies used?
      to detect specific proteins in chemically fixed, dead cells.
    • What is the purpose of chemical fixation in fluorescence microscopy?
      stabilises and preserves biological samples for microscopy.
    • What is the main goal of fluorescence microscopy?
      To locate and visualize cellular structures within biological samples.
    • how does confocal microscopy help with imagining 3D samples
      focusing on a single plane at a time and combining multiple images to create a three dimensional imagine
    • what is the primary benefit of using confocal microscopy
      improves resolution and allows for clearer imaging of samples particularly in three dimensions
    • What is the lattice light sheet microscope, and how does it differ from other microscopes?
      an advanced technique that uses a thin sheet of light to illuminate samples, allowing for high-speed, high-resolution imaging of live cells with minimal phototoxicity.
    • What is green fluorescent protein (GFP), and how is it used in fluorescence microscopy?
      can be attached to a specific protein as a tag for fluorescence microscopy. It is intrinsically fluorescent, making it visible in living cells.
    • How is GFP coding sequence added to a protein in molecular biology?
      can be added to a protein using molecular biology techniques, producing a fusion protein.
    • What are the potential problems with using GFP as a tag in fluorescence microscopy?
      a 238 amino acid, 25 kDa protein, and its size may alter the function of the protein it is attached to, potentially impacting the experimental results.
    • What is studied in the model organism, budding yeast?
      Protein synthesis and glycosylation in the ER
    • What is visualized in HeLa cells using GFP chimeras?
      Protein localization
    • What is studied in cultured cells regarding tyrosine kinase signaling?
      The interaction of FAK and src
    • What is visualized in HeLa cells regarding tyrosine kinase signaling?
      Their signaling
    • What is electron microscopy used for?
      Visualizing subcellular structures at higher resolution.
    • What is the difference between transmission electron microscopy and scanning electron microscopy?
      Transmission EM visualizes thin, stained samples for detailed subcellular structure, while scanning EM sees the surface of 3D structures.
    • How can transmission electron microscopy be enhanced?
      It can be combined with antibody labeling for specific protein visualization.
    • What type of microscopy uses thin, stained samples to visualize detailed subcellular structure?
      Transmission electron microscopy
    • How can transmission electron microscopy be combined with other techniques?
      with antibody labeling to highlight specific subcellular structures.
    • What does scanning electron microscopy allow us to see?
      the surface of three-dimensional structures.
    • What is the purpose of cell fractionation?
      To separate cellular components based on their size and density.
    • What happens when a suspension is centrifuged during cell fractionation?
      Heavier particles sediment at lower centrifugal force.
    • Name some cellular components that can be separated through cell fractionation.
      Nuclei, mitochondria, endoplasmic reticulum (ER), Golgi apparatus, and cytosol.
    • What technique is used to separate and isolate particles from a suspension?
      Centrifugation
    • At what centrifugal force do heavier particles sediment?
      lower centrifugal force.
    • What is SDS in gel electrophoresis?
      an ionic detergent that binds to proteins, giving them a negative charge and denaturing/unfolding them.
    • What is the function of polyacrylamide in gel electrophoresis?
      forms a mesh-like gel through which charged proteins move, with the speed of movement depending on their size.
    • How are proteins separated in gel electrophoresis based on size?
      proteins are separated by size, with smaller proteins moving faster and further through the gel.
    • What type of gel is used in SDS-polyacrylamide gel electrophoresis?
      SDS-polyacrylamide gel is used
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