Cells

• A bilayer of phospholipids that is semi-permeable + has lots of proteins

  • Fatty acid chains of the phospholipids point inwards, making the interior of the membrane hydrophobic 

  • Hydrophilic heads of the phospholipids point outwards

    • This allows the membrane to remain intact within an aqueous environment while still being impermeable to water-soluble substances 

  • A phospholipid bilayer also surrounds individual organelles in eukaryotes

 Cytoplasm

• Refers to cytosol (gel-like liquid within a cell) and the organelles + other things floating around (excluding the nucleus)

Cytoskeleton

• A membraneless structure made of protein fibers

  • Maintains/changes cell shape

  • Secures some organelles

  • Enables cytoplasm and vesicle movement

  • Allows cell to move