Flashcards
Secondary structures
Cards in this deck (5)
- 1rules on protein structures1) no rotation around rigid planar peptide bond - resonance gives partial double bond
2) other parts of the chain must be flexible - R groups define Psi and Phi
3) structure must have maximum no. of stabilising forces between residues - 2secondary structures- alpha helix
-B sheet
These are thermodynamically stable structures and polypeptides will spontaneously adopt these secondary structures very rapidly - 3alpha helix- HB are in the backbone
- top view has N-C going clockwise with the side chains projecting outward to do their jobs
- amphipathic helix = Hphobic one side and Hphillic on the other side = can arrange well in environments
- can't have glycine bc the chiral carbon reduces the flexiblity - 4B sheets- can be parallel or anti
- anti has more H bonds (more stable)
- H bonds form between COOH and NH2
- side chains can be above or below
- within one peptide chain - 5Phi and PsiPhi is between C and NH
Psi is between C and COOH
Information
- Description
- Macromolecules of Life (2) Protein types, structures n bonds) Flashcards on Secondary structures, created by Fatima Farhan on 03/01/2019.
- Created by
- Fatima Farhan
- Views
- 0
- Rating