Proteins Flashcards
Which form are all amino acids in ?
L optical isomer
Hydrophobic
Glycine Alanine Proline Valine Leucine Isoleucine Tryptophan Phenylalanine
Hydrophilic
Serine Theory one Tyrosine Asparagine Glutamine Cysteine
Positively charged side chain
Arginine
Lysine
Histidine is protonated (+) under pH 6
Negatively charged
Glutamate
Aspartate
Why can proteins not tolerate a great change in pH?
Ionisation state of amino acids is essential for function.
Changes in pH = change in ionisation state = change in property
Amino acids can take up and release protons = gives them capacity to resist some changes in pH
When do disulphide bridges form?
Cytosine chains oxidise
Covalent bond between 2 amino acids
Why does proline cause a kink in the peptide chain?
When proline is added = loss of NH group
Side chain can’t form hydrogen bonds with C=O of another part of chain
KINK
What is a parallel beta strand?
Beta sheets run parallel to each other
Beta sheets run anti parallel = antiparallel beta sheet
How does warfarin work?
Glutamate needs to be converted to gamma-carboxylglutamate
This is needed for calcium binding
Warfarin inhibits this reaction