BIOL 101 Lecture Notes - Lecture 9: Lipid Bilayer, Nuclear Membrane, Endoplasmic Reticulum
Document Summary
The plasma membrane is a phospholipid bilayer with embedded proteins that separates the internal environment of the cell from the surrounding environment. If you recall, phospholipids are lipid molecules with two fatty acid chains and a phosphate-containing group that forms a phospholipid bilayer. The bilayer also contains proteins and cholesterol embedded within. Functions: controls the passage of organic molecules, ions, water, and oxygen into and out of the cell as well as waste materials (i. e. carbon dioxide and ammonia) out of the cell, cytoplasm (makes majority of the cell) The cytoplasm is the entire region in the cell between the plasma membrane and the nuclear envelope (i. e. the membrane that separates the nucleus from the cytoplasm) Comprised of organelles suspended in the gelatinous cytosol, the cytoskeleton, and various chemicals. Consists of 70-80% water, other molecules (including proteins, glucose, other polysaccharides, amino acids, nucleic acids, fatty acids), and ions (sodium, potassium, calcium, etc. ) within the cytoplasm.