Internal membranes and enzymes

• Cell membrane structure


  A double layer of lipids with embedded specialised protein molecules
• Passive transport


  Cell transport that does not require energy
• Active transport


  Cell transport that requires energy
• Active transport


  Substances move from an area of low to high concentration
• Passive transport


  Substances move from an area of high to low concentration
• Calculate SA:V of a cube

  1. SA = 6 x 0.25 x 0.25

  2. V = 0.25 x 0.25 x 0.25

  3. SA ÷ V = 0.38 ÷ 0.02
• SA:V of a cube with dimensions 0.25 x 0.25 x 0.25 cm is 19:1
• Calculate SA:V of a spherical cell

  1. SA = 4πr²

  2. V = πr³

  3. SA ÷ V = 0.785 ÷ 0.065
• SA:V of a spherical cell with a 0.25cm radius is 12:1
• As a cell increases in size


  Its SA:V gets larger
• Primary energy source in cells

  Glucose
• Eukaryotic cells have a membrane bound nucleus
• Eukaryotic cells are more complex than prokaryotic cells
• Eukaryotic cells are usually smaller than prokaryotic cells
• Eukaryotic cells are believed to have evolved more recently than prokaryotic cells
• Plasma membrane


  If a cell has a plasma membrane, it can be either prokaryotic or eukaryotic
• Cell structure not found in both prokaryotic and eukaryotic cells


  Nucleus
• Chloroplast presence


  If a cell has a chloroplast, it is eukaryotic
• Organelle converting chemical energy

  Mitochondrion
• Prokaryotes


  • Bacteria
• Function of the nucleus

  Stores DNA
• Cell's boundary from its environment

  Cell membrane
• This is a eukaryotic cell because it has a nucleus and membrane-bound organelles
• Organelle identified


  Mitochondria
• This is a plant cell because a cell wall is present
• Calculate total magnification


  Total Magnification = objective lens size x eyepiece lens size
• Total magnification with 10x eyepiece and 10x objective lens is 100x
• Calculate FOV


  FOV = Diameter of microscope x 1000
• FOV when diameter of microscope is 3.5mm is 1500µm
• Internal membranes and enzymes are the focus of Unit 1 – Topic 1
• Learning intention


  I am learning about internal membranes and enzymes
• Success criteria


  I can explain how the arrangement of internal membranes can control biochemical processes
• Membrane bound organelles


  Provide distinct compartments which separate different reactions
• Compartments allow certain substances to be encased within specific areas
• The mitochondria increases its internal surface area by folding and stacking internal membranes
• Structural components of the mitochondria

  Outer membrane, inner folded membrane, cristae, mitochondrial matrix
• Outer membrane function


  Contains proteins and enzymes which transport substances into/out of the organelle
• Inner folded membrane function

  Contains enzymes needed for cellular respiration
• Function of cristae


  Increases the SA of the inner membrane
• Function of the mitochondrial matrix

  Contains enzymes in solution responsible for other reactions in cellular respiration