BIO SCI 93 Lecture Notes - Lecture 4: Van Der Waals Force, Beta Sheet, Disulfide

• School: UC-Irvine
• Department: Biological Sciences
• Course: BIO SCI 93
• Professor: Busciglio/ Wood/ Green

Document Summary

Lecture 4: proteins and nucleic acids study notes. Support, storage, transport, signaling, receptors, movement, catalysis, defense. Polypeptide: polymer of amino acids in specific sequence. Proteins: one or more polypeptides with specific 3-d conformation. There are three levels of structure in a single polypeptide that organize the folding. To perform their functions, proteins must fold properly. Pertaining to drawing: an enzyme that catalyzes the destruction of the cell walls of certain bacteria, occurring notably in tears and egg white. Hydrogen bonding by atoms in the backbone (n-h----o=c) Chaperone proteins promote proper folding and refolding by providing the appropriate environment. Protein degradation is as essential to the cell as protein synthesis. There are two major intracellular devices in which damaged or unneeded proteins are broken down: Extracellular proteins, e. g. , plasma proteins, that are taken into the cell, e. g. , by endocytosis. Cell-surface membrane proteins that are used in receptor-mediated endocytosis. The proteins (and other macromolecules) engulfed by autophagosomes.