Analysis of cell components

• What are the two key terms defined in microscopy?

  Magnification and resolution
• How do you calculate the actual size of an object?

  Image size divided by magnification
• How do you calculate the magnification of a microscope image?

  Size of image divided by actual size
• What is the importance of prefixes like milli, micro, and nano in microscopy?

  They help convert between different measurement units
• Why is resolution important in microscopy?

  It determines the detail visible in an image
• What are the two types of microscopes mentioned?

  Optical light microscope and electron microscope
• What are the two types of electron microscopes?

  Transmission electron microscope (TEM) and scanning electron microscope (SEM)
• What is the formula for calculating magnification?

  Magnification = size of image ÷ size of real object
• If an image is 25 mm wide and the real object is 0.25 mm, what is the magnification?

  ×100
• How do you calculate the size of a real object if the image is 1 mm and magnification is ×50?

  Size of real object = 1 ÷ 50
• What are the units used in microscopy?

  mm, µm, nm
• How many times bigger is a micrometre compared to a millimetre?

  1000 times bigger
• How many nanometres are in a micrometre?

  1,000,000 nanometres
• How do you convert from a smaller unit to a bigger unit?

  Divide by 1000
• What happens during homogenisation in cell fractionation?

  Cells are broken open to release organelles
• Why should the homogenate be kept cold during homogenisation?

  To minimize enzyme activity
• What is the purpose of filtration in cell fractionation?

  To remove large debris from the mixture
• What is ultracentrifugation used for in cell fractionation?

  To separate organelles based on density
• How are organelles separated during ultracentrifugation?

  By spinning at increasing speeds
• What is the order of organelles separated in ultracentrifugation?

  Nuclei, mitochondria, lysosomes, ER, ribosomes
• What is the formula for calculating the magnification of a microscope?

  Magnification = size of image ÷ size of real object
• What is the difference between magnification and resolution?

  Magnification enlarges, resolution clarifies details
• What is the numerical aperture in microscopy?

  A measure of light-gathering ability
• At what magnification can you see an optical microscope?

  Up to ×1000
• At what magnification can you see an electron microscope?

  Up to ×2,000,000
• Which microscope has a higher maximum magnification?

  Electron microscope
• What type of microscope would you use to study lysosomes?

  Electron microscope
• How do transmission electron microscopes (TEM) work?

  They transmit electrons through a specimen
• How do scanning electron microscopes (SEM) work?

  They scan the surface with electrons
• What is one advantage and one disadvantage of TEM?

  Advantage: High resolution; Disadvantage: Complex preparation
• What is one advantage of light microscopes?

  They are easy to use and prepare
• What is microscopy and how does it work?

  Microscopy is the use of microscopes to view small objects
• How do you make and stain microscopic slides?

  Prepare specimen, place on slide, add stain
• How did early scientists distinguish between artefacts and organelles?

  By observing consistent structures in multiple samples
• What are two methods of homogenisation for cell fractionation?

  Blender and mechanical disruption
• What happens during the filtration step of cell fractionation?

  Large debris is removed from the homogenate