Chapter 4 Flashcards
average molecular weight of an amino acid
110
How do you approximate the number of amino acids in a protein?
dividing the proteins molecular weight by 110.
smallest protein
insulin: ~50
biggest protein
titin
The 3D structure of a protein is determined by…
its amino acid sequence
the most important forces stabilizing the specific structures of a given protein are…
non-covalent
low free energy means…
most stable
Folded proteins occupy a….
low-energy state
Protein folding _________ the order.
increases
denaturation
loss of activity; reversible (energy required is small)
Folding and unfolding is a ______________ process
cooperative
cooperative process
as soon as some come apart, it all comes apart
Within main-chain of the polypeptide, there is a repeating pattern of…
NCCNCC
To represent a viable form of secondary structure, the folding pattern must:
- optimize the hydrogen bonding potential of main chain carbonyl and amide groups
- represent a favoured conformation of the polypeptide chain
There are _____ numbers of hydrogen bond donors and accepts within the polypeptide main chain.
equal
most residues within biological peptides and proteins tend to be in….
trans configuration
Trans configuration can’t convert to cis without….
breaking bonds
Each alpha carbon is held within the main chain through…
single bonds with complete freedom of rotation
Phi
alpha carbon to amide nitrogen
Psi
alpha carbon to carbonyl carbon
Ramachadran Plot
Illustrates all possible combos of Phi and Psi