ENDOMEMBRANE SYSTEM

• The endoplasmic reticulum (ER) is an interconnected network of membranes that extends throughout the cytoplasm.
• The endomembrane system is made up of different organelles. It starts with the nuclear envelope, endoplasmic reticulum, golgi apparatus, vesicles, lysosomes, vacuoles and plasma membrane.
• The ER has two types - rough and smooth
• Moving proteins in and out of the cell:

  1. We synthesise the proteins
  2. When ready, we label and package them called the golgi apparatus
  3. Then we deliver them using vesicles, which transport proteins from place. the membrane can fuse with membrane organelles.
• the endoplasmic reticulum has 2 types called:

  1. smooth (sER)
  2. rough (rER)
• The function of endoplasmic reticulum is to synthesize and transport lipids and proteins, detoxifying drugs and poisons that harm the cell. they also store calcium ions because it is a signal and can be released from the cell.
• rER function?

  They are involved in protein synthesis, making protien cells all the time. the proteins being secreted will be placed in the rER as they will get modified and changed in different ways to get a lesser structure to help with their function.
• Golgi apparatus makes sure the proteins get somewhere. They are a series of membrane bound flattened layers of structures.
• The Golgi Apparatus function?

  The vesicle will recieve proteins that were made to the golgi and then fuse together and then the proteins will be inside the lumen. From there, we are able to modify the protein and ship them off.
• Golgi Apparatus function has a polarity called cis-face and trans-face.
• Cis face faces towards the endoplasmic reticulum. The vesicles will arrive here.
• Trans-face faces towards the plasma membrane. After all the modifications happen, the vesicles will butt away from the trans-face.
• Glycosolation adds or modifies carbohydrate proteins to determine the function of the protein producing polysaccharides.
• Sorting proteins need to end up in the correct vesicles, so they add markers or tags to direct them.
• Direct vesicle trafficking is when short proteins are embedded into the surafce of the vesicle surface. There will be docking sites for the proteins to bind protein to the vesicle.
• Types of vesicles are membrane bound organelles with a bit of fluid.

  • Transport vesicles can move things from one place to another inside the cell.
  • Secretory vesicles can head to the plasma membrane to release their contents
  • Vacuoles