cheat sheet cell 1 - DNA-> RNA-> protein (gene...

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DNA-> RNA-> protein (gene expression) o Information that is carried into action by proteins (gene products) Covalent bonds and ionic bonds hold molecules together. Other bonds determine the association between diff mol (electrostatic interactions [strong bonds/ easily separated by water], hydrogen bonds [weak, weakened by competition of water], van der Waals attractions [weak interactions between non-polar atoms/no effect by water/nonspecific], hydrophobic forces[occurs due to lowest energy conformations/nonspecific-not effected by water]) A means for predicting if a reaction process will occur G=H-TS o Free energy (G) and eq points can be used to describe reactions and determine their likelihood of occurrence o - G- spontaneous +G-not spontaneous o release of heat H and an increase in S increases the likelihood of a reaction occurring o making molecules and keeping a cell ordered requires energy H and decreases entropy S o couple a large favorable reaction with a smaller unfavorable reaction overcomes +G primary-seq of a.a (polymer) o each a.a has its own chemical behavior based on its side chain (basic, acidic, uncharged polar, nonpolar) secondary-basic units of shape (a helix and b sheets) tertiary- full 3D shape and one polypeptide quaternary-3D shape of associated polypeptides Domains are independ folding regions of a peptide chain Proteins work by binding – surface surface, helix helix, surface string Proteins as enzymes – work by binding too, increase likelihood of a rxn (bring reactants in close proximity, alter electron distribution to favor rxn, bind more favorably to the transition state) they lower activation energy and speed up rxn. They are specific. Control enzymatic activity by structure-func, change the env, phosphorylation with protein kinase (add of neg charged functional group) change shape Proteins need to fold quickly o Misfolded may be destroyed by proteasomes o Misfolded proteins often have exposed hydrophobic pathes Chaperones recognize exposed hydrophobic patches of misfolded proteins and aid in refold o Hydrophobic regions bond non-spec, will stick together indiscriminately forming protein aggregates o Hsp 70 works with hsp40 early in folding, multiple times o Hsp 60 provides a special space for folding and favorable environment Proteasome unfoldase AAA enzyme complex o Protein degradation- compete with folding pathways, slower a proteins is to fold the more likely it is to get captured by the degradation pathways o Requires ATP for protein threading bc needs to break H bonds o Flagging misfolded protein with ubiquitylation E1 = activating enzyme and E2&E3= ubiquitin ligase Polyubiquitylation- chain required for degradation
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Removal of a protein is effective to turn it off (regulation) Prion- can influence the folding of other subunits….amyloid- fibers through misfolded protiens. Bovine spongiform encephalopathy and Kuru and scrapie Cell membrane protects the cell, increase opp for regulation, barriers for creating work
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This note was uploaded on 02/28/2009 for the course CELL BIO 50120 taught by Professor Bushart during the Spring '09 term at University of Texas at Austin.

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cheat sheet cell 1 - DNA-> RNA-> protein (gene...

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