Cell membranes

a mind map of chapter 2 cell membranes

HideShow resource information
  • Created by: samsam001
  • Created on: 17-03-14 19:24
View mindmap
  • cell membranes
    • Overview
      • Every living cell is surrounded by a cell membrane
    • Functions
      • Membranes are partially permeable, they control what enters and leaves the cell
      • Membranes produce different compartments inside cells
      • Membranes are important in cell signalling
      • They allow electrical signals to pass through them
      • Membranes provide attachment sites for enzymes and any other molecule involved in metabolism
        • mechanisms of cell signalling
          • receptor acts as an ion chanel
            • the signal is a chemical that attaches to a protein or a glycoprotein acting as an ion channel. When the chemical attaches to the receptor it opens, letting the ions in.
          • receptor activates a G-protein
            • Here the receptor in the plasma membrane interacts with another molecule, a g-protein.
              • When the signal molecule attaches to the receptor, the G-protein is activated
                • the g-protein the activate an enzyme which brings about the reaction
    • Structure
      • all have similar structure. they are normally between 7-10 nm. Meaning they are invisible under a light microscope, but visible with an electron microscope
      • They are formed of a double layer of molecule called phospholipids,which have many proteins in them
    • Phospholipid bilayer
      • Phospholipids have hydrophilic head and hydrophobic tail
      • the cytoplasm has a lot of water and so does the outside. the hydrophilic heads are therefore attracted to the fluids and the tail isn't so this forms a double layer with the heads facing the fluids and the tails facing each other
    • membranes also contain cholesterol, glycoproteins and glycolipids
    • Fluid mosaic model
      • fluid refers to the fact that the molecules in the membrane are in constant motion
      • mosaic refers to how it would look from above
    • cell signalling
      • cells must stay in contact in order to survive
      • in multi-cellular organisms, cells in one part need to communicate with cells in another
      • Signals arrive at the plasma membrane from the outside, i.e a hormone
        • a receptor in the cells plasma membrane receives the signals and brings about actions, this is called cell signalling
    • mechanisms of cell signalling
      • receptor acts as an ion chanel
        • the signal is a chemical that attaches to a protein or a glycoprotein acting as an ion channel. When the chemical attaches to the receptor it opens, letting the ions in.
      • receptor activates a G-protein
        • Here the receptor in the plasma membrane interacts with another molecule, a g-protein.
          • When the signal molecule attaches to the receptor, the G-protein is activated
            • the g-protein the activate an enzyme which brings about the reaction

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Cell Membranes resources »