Lesson 2

• What defines eukaryotic organisms?

  Cells contain a nucleus and organelles
• What is an organelle?

  A subcellular structure with specific jobs
• What is the cellular ultrastructure of humans?

  • Humans are made of cells
  • Cells consist of organelles
  • Organelles are structurally and functionally distinct
• What surrounds the nucleus?

  A double membrane called the nuclear envelope
• What is the role of the nucleolus?

  Site of ribosome and rRNA production
• What is the function of the nucleus?

  Contains DNA and regulates cell activity
• What is the structure of mitochondria?

  Outer and inner membranes with cristae
• What is the primary function of mitochondria?

  Carry out aerobic respiration to provide ATP
• What are the functions of rough and smooth endoplasmic reticulum?

  • Rough ER: synthesizes and transports proteins
  • Smooth ER: synthesizes and transports carbohydrates and lipids
• What is the function of the Golgi apparatus?

  Packages, sorts, and modifies proteins
• What are vesicles used for in a cell?

  Transport materials within the cell
• What is the function of lysosomes?

  Destroy damaged organelles and bacteria
• What are ribosomes made of?

  Two subunits of protein and rRNA
• What is the role of centrosomes during cell division?

  Forms the spindle during cell division
• What is the structure of the cell membrane?

  Bilayer of phospholipids with proteins
• What does the Fluid Mosaic Model describe?

  The structure and function of the cell membrane
• Why do phospholipids arrange themselves in a bilayer?

  Due to hydrophilic heads and hydrophobic tails
• What is the purpose of cholesterol in the cell membrane?

  Regulates fluidity and stability of the membrane
• What are the functions of glycoproteins in the cell membrane?

  • Involved in cell recognition
  • Act as receptors for signaling molecules
  • Stabilize membrane structure
• What are the functions of glycolipids in the cell membrane?

  • Act as recognition sites and antigens
  • Increase membrane stability
• What is the best light microscope resolution for organelles?

  Can view organelles the size of mitochondria
• What is the formula for magnification?

  Magnification = Observed size / Actual size
• How do you convert 2 mm into nanometres?

  2 mm = 2,000,000 nm
• What are the steps to convert between mm, µm, and nm?

  1. 1 mm = 1000 µm
  2. 1 µm = 1000 nm
  3. Use these conversions for calculations
• What is the role of carbohydrate chains in the cell membrane?

  Act as recognition sites and stabilize membrane
• What is the significance of the hydrophilic and hydrophobic properties of phospholipids?

  They determine the bilayer arrangement in membranes
• How do glycoproteins and glycolipids function similarly in the cell membrane?

  Both act as recognition sites and stabilize membranes