L2 prot fold and func

Question 1

LO1: prim, sec, ter, quart struc. feats of two main sec strucs alpha helix and beta sheet.

Answer 1

-prim- lin aa seq polypep. cov bonds. anglea around C-N determ fold.
-sec- loc spat arr of pp backbone.
alpha helix 0.54nm pitch 3.6aa. H bond btw carbonyl O and amide H 4 aa apart. Rs outside tight packed core. ala and leu strng helix formers. pro breaks as no rotat around N-Ca. gly breaks as small R supp other confs.
beta strand extended, 0.35nm btw aa, R alt opp sides chain. antipar sheet adjac opp, H bond btw. paral H bond diff angle. can get mixed.
-tert- 3d arr of all atoms in pp. fold of sec so far apart aa’s interac. glob var tert struc-motif=fold patt cont 1+ elem of sec struc eg beta alpha beta loop, beta barrel. domain= part of pp chain that fold distinct shape often for specif func.
-quart- 3d arr of prot su’s. non cov hold.

Question 2

LO2: Types of bonds. How disrup=denat.

Answer 2

• prim- cov
• sec- H bond.
• tert and quart- cov(disulph), ionic, H bond, VDW, phob interacs.
• denat as not v stable. heat incr vib eberg. pH alt ionisat state, alt ionic/H bonds. deterg/organ solvent disrup phob interacs.