section 3

• The structure of a cell membrane is made of a lipid bi-layer of phospholipids.
• Phospholipids have a polar glycerol head that attracts water making it hydrophilic and 2 non-polar fatty acid tails that repel water making it hydrophobic.
• Another name for cell membrane is plasma membrane.
• Lipid bi-layer means a double layer of lipids.
• There are 2 functions of the cell membrane: selective permeable barriers and proteins embedded in the membrane have specific jobs.
• The selective permeable barrier allows some things to enter and leave the cell which helps maintain homeostasis.
• Proteins embedded in the membrane have specific jobs: cell surface marker, receptor proteins, transport proteins and enzymes.
• The cell surface marker identifies cell type.
• Receptor proteins recognize and bind to substances outside the cell.
• Transport proteins help move substances across the cell membrane.
• Enzymes assist chemical reactions inside the cell.
• The fluid mosaic model is a model of the cell membrane.