BIOC2000 Lecture Notes - Lecture 3: Lipid Bilayer, Beta Sheet, Micelle
Saturday, 9 June, 2018
Susan L03-04
Folding refers to protein backbone taking up space
-Weak forces drive folding (h bond and what Van der Waals’ force)
-Covalent bond restrict folding
-energy can be release when bond form or energy can be needed to break a bond
-- delta G shows spontaneous reaction; -ve delta G means energy release from bond
formation
-+ve delta G shows non-spontaneous reaction; -ve delta G means energy needed to
break bonds
-affinity includes shape matching and weak force interactions
-more weak force interactions means higher affinity
Structure of protein
- Secondary (Alpha Helix Beta sheet)
- Disulphide bonds are covalent bonds (SH-HS)
- Covalent bonds hold backbones together (peptide)
-Lipids do not form hydrogen bonds
-electronegativity of C and H are almost the same thus no much electronegativity
difference which leads no partial positive or negative charge; since no evenly shared
electron cloud; no h bond
-Weak forces are designed to be flexible
-When we cook an egg protein denature but not degrade
-We add heat when cooking increase kinetic energy; we break weak forces in primary
structure of protein but not covalent structure of protein which is 10 times stronger
than the weak forces thus do not degrade
-Weak forces are so weak that they fall apart all the time so they can interact with each
other
-Weak forces include
-Van der Waals’; charge charge; hydrophobic interaction; h bond and London
dispersion
Hydrogen bond
-Hydrogen is always the donor
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