Organelles, magnification and cell membranes

• Explain the role of nucleolus?

  It makes RNA and assembles ribosomes
• Explain the mitochondria structure?

  Double membrane structure, with folded inner membrane
• Explain the role of rough endoplasmic reticulum?

  Used for proteins synthesis
• Explain the function of smooth endoplasmic reticulum?

  It makes lipids and steroids
• Explain the function of Golgi apparatus?

  It modifies protein
• Explain the function of vesicles?


  To carry protein to the plasma mebrane so it can be released outside the cell
• Explain the plasma membrane (Cell surface)?

  Under a light microscope, a cross section of the membrane looks like a single line. However, using an electron microscope with closer examination reveals that it's a bilayer.
• What is the basic structure of the plasma membrane (cell surface)?

  consists of two layers of phospholipids
• What does a phospholipid consist of?

  It consists of two fatty acids bonded to glycerol with eater bonds and a phosphate group.
• What does a phospholipids form?

  Bilayer
• Explain the fluid mosaic model?

  The cell surface membrane not only contains a phospholipid layer, it also contains proteins, glycoproteins, cholesterol and glycolipids
• When and who introduced the fluid mosaic model?

  proposed by two scientists, singer and Nicholson in 1972.
• What is fluid?

  The phospholipids move slighly from side to side
• What is mosaic?

  A random arrangement of proteins, phospholipids and cholesterol within the membrane
• Explain membrane transport?

  To survive, cells need to take in substances like oxygen and glucose, which are used for metabolism and remove waste products such as carbon dioxide. For the molecules to enter or leave the cell, they must cross the phospholipid bilayer.
• What are the 5 basic ways that molecules can cross over the cell membrane?

  Simple diffusion, facilitated diffusion, osmosis, active transport and bulk transport.
• Explain the difference between passive process and active process?

  Passive process does not need energy and active does
• Is simple diffusiion active or passive process?

  Passive
• Is facilitated diffusion active or passive process?

  Passive
• Is osmosis active or passive process?

  Passive
• Is Active transport active or passive process?

  Active
• Is bulk transport active or passive process?

  Active
• Explain simple diffusion and how can they cross the lipid layer?

  Small uncharged molecules or hydrophobic molecules can cross the lipid bilayer. They can diffuse between the phospholipids