BCH210H1 Lecture Notes - Lecture 5: Membrane Protein, Lipid Bilayer, Phosphatidylcholine

• School: UTSG
• Department: Biochemistry
• Course: BCH210H1
• Professor: Stavroula Andreopoulos

Document Summary

Membrane proteins: membrane proteins are responsible for key cellular processes, functions include transporters, channels, receptors, enzymes, embedded in lipid bilayer. Phosphatidylcholine molecule choline positively charged: head group, phosphate, acyl chains, phospholipids have two parts negatively charged fatty acids, hydrophobic, hydrophilic acyl chains head group. Calcium atpase pump: 1 polypeptide made of many sub-domains (n, p, a, M (membrane): requires atp at the atp binding domain, modifies aspartic acid to hydrolyze atp and put it onto the aspartic acid. In order for this protein to work, domains need to fold correctly. Sodium-potassium atpase: high potassium and low sodium inside of cells, atpase uses atp to pump. 3 sodium molecules out of cells and 2 potassium molecules into cell. Inside of cell is negative compared to outside: other transporters use sodium gradient to uptake amino acids, sugars, vitamins, etc, 1/3 of atp intake is used to maintain sodium-potassium atpases in cells.