Flashcards
Lectures 1-3 Rice
Flashcards do conjunto (22)
- 1What isomer do most biological amino acids exist as?L-isomers
- 2In what direction do polypeptides go?N terminus to C terminus
- 3What bond in polypeptides is the ϕ bond?Phi bond, Cα-NH
- 4What bond in polypeptides is the Ψ bond?Psi bond, Cα-COO
- 5How many residues per turn in an alpha helix?3.6
- 6What are structure motifs?Arrangements of a few helices or sheets
- 7What are super secondary structures?Common motif structures
- 8What are domains?Distinct divisions of one polypeptide, specific functions
- 9What are homo oligomers ?many copies of the same polypeptide
- 10What are hetero oligomers?Copies of different polypeptides
- 11What are the main techniques used to discover protein structures?X-ray diffraction, NMR, cryo electron microscopy
- 12Why are disulphide bonds more common in extracellular proteins?To give them more stability in the hostile environments
- 13What is the function of Ribonuclease A?Cleaves ss ribonucleic acids
- 14Where is RNase found?Pancreas
- 15Why is beef pancreas usually used to isolate RNase?Very abundant
- 16What bond does RNase cleave?P-O5' in backbone after a pyramidine
- 17What is the key catalytic intermediate formed during the reaction involving RNase?2'-3'-cyclic nucleotide
- 18What are the two main steps in the RNase reaction?Formation of intermediate, its cleavage
- 19What does the pH profile of hydrolysis of the intermediate look like? What does it show?Suggests there has been a titration, as a result of two residues donating and accepting protons
- 20What are the two key residues in the active site?Two His residues because they titrate around pH 6-7 which matches the pH profile. One acts as an acid and one as a base. His12 and His 119.
- 21Describe the tertiary structure of RNase3 stranded, Ushaped, anti parallel beta sheets, three short alpha helices. Lys 41 stabilises the negative phosphate in intermediate. Phe120 forms vdw contacts with RNA, Ser123 and thre45 forms H bonds. Too small for purines to fit in active site
- 22What does angiogenin do?Promotes development of the blood vessels.
homologue of RNase
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- MBB266 - Biostructures, energetics and synthesis FlashCards sobre Lectures 1-3 Rice, criado por Kayla Price em 28-09-2018.
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- Kayla Price
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