Cells as the basic unit of life

• Living Organisms are made up of cells
• Organelles are smaller components, within a cell , that have a specific function.
• Atoms -> Molecules -> Organelles -> Cells
• Unicellular - 1 cell

  Multicellular - lots of cells

  Organelles - The brain, heart etc.
• Atoms -> Molecule -> Macromolecule -> Organelles -> Cells
• Organelles:

  -Nucleus

  -Cytoplasm

  -Mitochondria (do not draw in diagram as they are not seen under microscope)

  -Chloroplasts

  -Cell membrane

  -Cell wall

  -Vacuole
• Cell Specialistaion:

  Villi Epithelic cells

  finger-like folds location

  • small intestine help - increase surface area = increase absorption

  The outer layer of the villi is made up of villi is made up of villi epithelical cells (lining of cells for absorption)
• Cell Specialistaion:

  Villi Epithelic cells

  finger-like folds

  location - small intestine

  help - increase surface area = increase absorption

  The outer layer of the villi is made up of villi epithelical cells (lining of cells for absorption)
• Villi:

  Lined with a dense network of blood vessels ---> This allows absorbed nutrients to be efficiently transported by the circulatery system

  Villi are folded = Increase surface area
• Cell Specialistaion:

  Villi Epithelic cells

  The Cell:

  The microvilli are there to furthur increase surface area.

  The cells have numerous mitochondria (supply the cell with energy required for absorbtion)

  
• Red Blood Cell:

  Carries oxygen from the lungs to the body cells.

  Have a Biconcave shape to increase surface area of the cell

  Relatively small and flexible to fit i narrow blood vessels

  Have no nucleus for more space available for oxygen absorption
• Sperm Cells:

  Have strong tails to manage to swim to the ovum

  Have lots of Mitochondria to move

  Has a head that can digest the outer egg wall
• Palisade Cells:

  Usually long and columnar shaped - to be tightly packed together

  - for as much light absorption as

  possible
• Root Hair cell:

  Absorb water and nutrients from the soil

  Have a root hair - to increase surface area

  Have no chloroplasts - do not preform photosynthesis (as they are found in the soil so they do not recieve any sunlight)

  Have Mitochondria - high energy needed for absorption
• Cellular Organisation of multicellular organisms:

  Organelles -> Cells -> Tissue -> Organs -> Organ System

  Muscle cell -> Muscle Tissue -> Organ -> Organ System

  Atom -> Molecule -> Macromolecule -> Organelle -> Cell -> Tissue -> Organ -> Organ System