IMG_2286.jpeg

# Ch. 3 Cell Notes **Cell Theory** - First described by Robert Hooke in the 1600s - Human cells are either somatic (body) or sex cells (reproductive) - Cells range in size from 10 to somicrometers - Cells are 60.1% water **Cell Parts** 1. All living organisms are made of cells 2. All cells come f...

# Ch. 3 Cell Notes **Cell Theory** - First described by Robert Hooke in the 1600s - Human cells are either somatic (body) or sex cells (reproductive) - Cells range in size from 10 to somicrometers - Cells are 60.1% water **Cell Parts** 1. All living organisms are made of cells 2. All cells come from pre-existing cells 3. Cells are the structural and functional units of living things **Cell Membrane (plasma membrane)** 4 General functions 1. Physical isolation 2. Regulation of exchange with the environment 3. Sensitivity to the environment 4. Structural Support **Membrane Lipids** Phospholipid bi-layer - two layers of lipids with hydrophilic heads comprising the inner and outer surfaces of the membrane. Hydrophobic tails point to each other making the inner portion of the bi-layer. Hydrophobic tails prevent water from moving through the bi-layer.