Protein Levels Flashcards
what is the primary level
sequence of amino acids in backbone
what is the secondary level
localised organisation of backbone
what are motifs
regular combination of secondary structure
what are domains
a functional unit of protein
what are teritary levels
overall shapes of protein
what are quaternary levels
interactions between more than one polypeptide to form multimers
what do sequences of amino acids fold into
alpha and beta sheets due to hydrogen bonding between N-H and C=O atoms
what is the alpha helix
H-bonds form between 4th amino acids
what is the beta sheet
H-bonds form between amino acids in different chains, can be parallel or anti-parallel
how are motifs formed
alpha + beta + other features = motifs
what is a helix-loop-helix
held together by weak interactions between mineral calcium and amino acids
what is the zinc-finger
2 B strands and alpha helix held by interactions with zinc
what is a coiled-coil
common in fibrous proteins and formed in alpha helixes with more hydrophobic residues
what gives overall structure
secondary structures + motif or domain = overall structure
what is an example of a domain
antibody variable domain
what are prosthetic groups
small molecules from vitamins and minerals that give proteins extra functions
what is retinol
found in purple-light sensitive proteins and comes from Vitamins A and is surrounded by a cage of alpha helixes
what are multimers
multiple proteins assembled together
what does changing the position of the binding site cause
long fibres/rings generate from the same protein
proteins with the most interactions at the binding site mean what
interact most stably
why is quaternary structure called alpha2beta2
4 subunits, fall into 2 types alpha or beta and these have different territory shape
what are conformational changes
these are important for protein function and are initiated by binding of other molecules. They change from one stable folded shape to other
