Protein Structure Flashcards
A characteristic shown by proteins when they are structural:
More rigidity and less flexibility.
What determines the function of a protein?
The 3D structure determines the function of a protein.
What are proteins?
Amino acids linked by peptide bonds and these form polypeptide chains. (protein often has 1 or more polypeptide chains.
What is the direction of a polypeptide chain?
N - terminus to C - terminus. ( N - terminus is the nitrogen group : NH3).
What are the forces // bonds which hold proteins together?
Van der Waals , Hydrogen , Ionic , Disulphide and Hydrophobic.
What happens to the peptide bond as a result of it being part of a resonance structure?
It is rigid and can’t rotate.
What are polypeptides?
Amino acids joined by peptide bonds to form a polymer.
What structures are produced when folding the polypeptide backbone?
Alpha helix and Beta sheet.
What are the two forms of beta sheet?
Anti - parallel and parallel.
What is the structure of collagen?
Three intertwined left - handed helices.
Why does brittle bone disease occur?
Substitution of another amino acid in place of glycine in collagen - Hence, the collagen can’t fold.
What are the symptoms of brittle bone disease?
Multiple bone fractures // bone deformity // respiratory problems
What bonds stabilise a tertiary protein structure?
Hydrogen bonds
Disulphide bonds
What are the compact globular regions in a protein called?
Domain
What is a tetramer?
It is made up of 4 subunits (4 polypeptide chains).
