The cell membrane
Download
1 / 28

The Cell Membrane - PowerPoint PPT Presentation


  • 99 Views
  • Updated On :
  • Presentation posted in: General

The Cell Membrane. What is the cell membrane?. AKA: Plasma membrane The boundary between the cell and the environment Does every cell have a cell membrane? Yes, Each and every cell has a cell membrane. Cell membranes help maintain homeostasis, what is that?. Cells breathing

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

The Cell Membrane

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript



What is the cell membrane l.jpg
What is the cell membrane?

  • AKA: Plasma membrane

  • The boundary between the cell and the environment

  • Does every cell have a cell membrane?

    • Yes, Each and every cell has a cell membrane.


Cell membranes help maintain homeostasis what is that l.jpg
Cell membranes help maintain homeostasis, what is that?

  • Cells breathing

  • Cells getting blood to them

  • Cells maintaining internal conditions

  • Cells reproducing


How do cell membranes help to maintain homeostasis l.jpg
How do cell membranes help to maintain homeostasis?

  • The cell membrane allows nutrients to come into the cell

    • Glucose, amino acids, lipids

  • The cell membrane removes waste


  • Selective permeability l.jpg
    Selective Permeability

    • The cell membrane lets some molecules in and keeps others out

    • EX. A cell is low on glucose so the membrane lets in some glucose, but does not overfill the cell with the macromolecule.


    Structure of the cell membrane l.jpg
    Structure of the cell membrane

    • What does the cell membrane look like up close?

    Lets look at one of these structures up close


    Structure of cell membrane l.jpg
    Structure of cell membrane

    • Phospholipids

      • Phosphate head

      • Glycerol

      • 2 Fatty acid tails(lipids=fats, oils, etc)


    Phospholipids l.jpg
    Phospholipids

    • 1.) Phosphate Head

      • Polar

      • Hydrophilic

      • Make up the outer borders of the membrane

  • 2.) Fatty Acid Tails

    • Nonpolar

    • Hydrophobic

    • Make up the inner part of the membrane



  • Polar vs nonpolar l.jpg
    Polar vs. Nonpolar

    Polar- positive and negative ends (b/c electrons are not shared equally)

    Ex. Water

    Nonpolar- does not have oppositely charged ends (atoms share electrons equally)


    Why are the phospholipids arranged tail to tail l.jpg
    Why are the phospholipids arranged tail to tail?

    -b/c water is inside and outside the cell

    phosphate group is hydrophilic (polar) end

    -attracts water

    fatty acid tail end is hydrophobic (nonpolar)

    -repels water


    Structure of cell membrane12 l.jpg
    Structure of cell membrane

    • Phospholipid bilayer

      • 2 layers of phospholipids make up a cell membrane


    Phospholipid bilayer l.jpg
    Phospholipid Bilayer

    • Remember polar heads and nonpolar tails




    When something is hydrophilic it l.jpg
    When something is hydrophilic, it… inside & outside the cell

    • Has a chemical makeup that likes to be around water

    • Has a chemical makeup that does not like to be around water



    Other components of the cell membrane l.jpg
    Other components of the cell membrane inside & outside the cell

    • Cholesterol

      • Helps to stabilize the phospholipids and keep them from sticking together


    Other components of the cell membrane19 l.jpg
    Other components of the cell membrane inside & outside the cell

    • Proteins

      • Regulate which molecules enter and which molecules leave a cell.


    Types of proteins in the cell membrane l.jpg
    Types of proteins in the cell membrane inside & outside the cell

    • Carrier Protein

      • Allow needed substances or waste materials to move through the cell membrane


    Types of proteins in the cell membrane21 l.jpg
    Types of proteins in the cell membrane inside & outside the cell

    • Channel or Pore protein

      • Hydrophilic channel – allows lipid insoluble substances to pass in and out of cell.


    Types of proteins in the cell membrane22 l.jpg
    Types of proteins in the cell membrane inside & outside the cell

    • Glycoproteins

      • Protein with what macromolecule attached to it?

        • Carbohydrate

      • Functions for cell to cell recognition


    Types of proteins in the cell membrane23 l.jpg
    Types of proteins in the cell membrane inside & outside the cell

    • Receptor Protein

      • These have binding sites for molecules such as hormones or substrates to bind to


    Fluid mosaic model of cell membrane l.jpg
    Fluid Mosaic Model of Cell Membrane inside & outside the cell

    -lipid bilayer is not strong & firm like a hard shell, but it is fluid like a soap bubble (often called a fluid mosaic model)

    -individual phospholipids, arranged side by side, float within the bilayer (cholesterol prevents phospholipids from sticking together)


    Structure of cell membrane25 l.jpg
    Structure of Cell Membrane inside & outside the cell

    -nonpolar interior zone- true barrier that separates the cell from its surroundings

    many polar particles like sugars, proteins, ions, & most cell wastes cannot cross this zone b/c they are repelled by the nonpolar region


    Arrangement of cell surface proteins l.jpg
    Arrangement of cell surface proteins inside & outside the cell


    Cell membrane structure l.jpg
    Cell Membrane Structure inside & outside the cell


    Lets build a cell membrane together l.jpg
    Lets build a cell membrane together inside & outside the cell

    • http://www.wisc-online.com/objects/index_tj.asp?objid=AP1101


    ad
  • Login