proteins lec 4 Flashcards
globular proteins structure?solubility?
tertiary structure gives 3D arrangement
somewhat spherical
water soluble
(hydrophobic sidechains face inwards , hydrophilic face outwards)
what is the function of the tertiary structure
to recognise specific molecules
tertiary structure easy/hard to unfold/denature/misfold
easy to unfold/denature due to weak interactions
tertiary structure stability ?
marginally stability favoured in evolution as they can readily unfold/denature and be used for the production of more vital proteins
what’s the driving force of protein folding?
hydrophobic effect
_____ can’t interact favorably with water
hydrophobic side chain Val, Leu, Phe
During ____ the chain _____
protein folding
clusters together in the protein interior
_____ carries oxygen in ____
myoglobin
muscle
___ has # helices
myoglobin
8
most are amphipathic
_____ side chains ___ proteins
hydrophobic
buried inside
____ are ___ portions buried in ___ core of membrane
membrane proteins
hydrophobic
hydrophobic
_____ are interactions between protein structures. (explain)
van der waals
weak intermolecular attractions between uncharged molecules
numerous interactions
_____ hold secondary structure together
hydrogen bonds
hydrogen bonds provide ___ for proper folding of __
geometric restrains
protein
___ bonds can form between backbone C=O and N-H groups, or side chains _____
hydrogen
Ser, Asn, Thr, Asp
hydrogen bonds can form between ___
backbone
C=O
N-H groups
side chains (Ser, Thr, Asn, Asp)
ion pairs def
electrostatic attraction between oppositely charged side chains
In ___charge depends on pH, so interactions disrupted by ____ ___
ion pairs
pH
change
Disulphide bonds def?
covalent link between two cysteine residues (-SH HS- to -S-S-)
_______ don’t cause folding but provide extra stability
Disulphide bonds
metal ion coordination def?
ions with interactions on several parts of a amino acid chain, causing folding
proteins denature easily since __
they are only marginally stable
during protein denaturing ______
the interactions are disrupted, therefore, results in unfolding, causing the protein to lose function
Examples of denaturing agents ?
pH - charge
Temp- all interactions
organic solvents and detergents - hydrophobic interactions
reducing agents - disulphide bonds
What denaturing agent affects:
charge
hydrophobic interactions
disulphide bonds
pH
detergents and organic solvents
reducing agents
