chapter 4 cell biology Flashcards
Proteins fold into ____ that represent_____ ______
conformations energy minima
Unfolded proteins are said to be
denatured
Molecular chaperones
in the cell help proteins
fold into their correct conformations
A protein’s structure will be determined by
its primary sequence.
Relevant parts of the protein will be the _____ ________
and the side chains or ____ ______ of each specific
amino acid.
polypeptide backbone , R-groups
peptide bond is _____ and
has no ______ in this region.
plannar rotation
Proteins can fold into many possible _______
however energetics drives them to ____ ____ ___
for each protein
conformations, one stable conformation
Folding starts co-translationally which means
chaperone proteins are needed
Proteins can often refold by themselves in _______
solution
____________ bonds serve to generate structure
in proteins. These can occur between _________ &______ backbone.
Weaker, non-covalent, R groups or parts of the polypeptide
__________________ also are key to specific
_______ binding of proteins. This occurs through the formation of ______ _______
Weaker, non-covalent bonds, ligand, binding sites.
Which of the four types of amino acids is represented by the most members
non polar
Water interactions will often help to drive protein folding becuase
of its polar charge and the polar and non polar amino acids in proteins
A.a that are Charged residues are
acidic and basic)
A.a that Polar residues are are involved in
phosphorylation, glycosylation
(Ser, Thr, Tyr) are involved in
phosphorylation
(Asn, Ser, Thr)
glycosylation
Cysteine forms (3)
disulfide bridges)
intrapolypeptide, interpolypeptide
______ in proteins are part of tertiary structure.
They are often arrangements of linked regions of ____ _____ & _____ _____
Domains alpha helices and beta sheets.
________ ______ between domains can
provide a variety of functions.
Unstructured regions
R groups locally
are hydrophobic, so ___ ____ may be favored
alpha helices
alpha helices will tend to associate that region
of the protein into
membrane bilayers –
transmembrane domains
coiled-coils are formed by
hydrophobic a.a twist in a sturucure and then twist together
Beta sheets can have
either of two
arrangements
parallel or
anti-parallel
