cells

• Light microscopes use a pair of convex glass lenses
• Light microscopes have a lower resolution than electron microscopes.
• What is the definition of resolution in microscopy?

  Objects distinguished as separate
• There are two main types of electron microscope: TEM and SEM
• Electron microscopes require a vacuum environment to prevent electron deflection.
• How does a transmission electron microscope create an image?

  Electrons pass through specimen
• A scanning electron microscope uses electron scattering to build a 3D image
• What is the purpose of cell fractionation?

  Separate cell organelles
• Steps in differential centrifugation

  1️⃣ Cells are blended in an homogeniser

  2️⃣ Homogenate is spun at a slow speed

  3️⃣ Heaviest organelles form a pellet

  4️⃣ Supernatant is spun at a faster speed

  5️⃣ This process is repeated until all organelles are separated
• The homogenate is placed in a cold, buffered solution to prevent bursting under osmotic pressure
• What is the primary function of the rough endoplasmic reticulum?

  Processes proteins
• What is the function of pili in prokaryotic cells?

  Attach to other cells
• What is the role of mitosis in multicellular organisms?

  Growth and repair
• There are three stages of the cell cycle: mitosis, interphase, and cytokinesis
• Steps in cytokinesis

  1️⃣ Parent and replicated organelles move to opposite sides

  2️⃣ The cytoplasm divides

  3️⃣ Two daughter cells are produced
• What is the process called by which prokaryotic cells divide?

  Binary fission
• What is the arrangement of phospholipids in the cell membrane?

  Hydrophilic heads outward
• What is the function of glycolipids in the cell membrane?

  Cell surface receptors
• What attracts a phagocyte to a pathogen?

  Chemical products

  
• What is the outer boundary of a bacterial cell called?

  Plasma membrane

  
• What are the two layers of the lipid bilayer made of?

  Phospholipids

  
• What triggers a B-cell to become activated?

  Matching antigen

  
• What is the primary function of the antigen-binding sites on an antibody?

  Bind to antigens

  
• What does ELISA stand for?

  Enzyme-Linked Immunosorbent Assay

  
• What type of genetic material does the virus contain?

  RNA

  
• What is the function of the nucleus in an animal cell?

  Controls cellular activities

  
• What is the first step in cell fractionation as shown in the image?

  Homogenization