Proteins (c) Protein Structure, Ligand binging and conformational change (i) Flashcards
Amino Acid sequence determines…
Protein structure
Proteins are…
Polymers of amino acid monomers
Amino acids link by…
Peptide bonds to form polypeptides
Amino acids have the same…
basic structures, differing only in the R group present
Amino acids are classified according to…
Their R groups: Basic (positively charged); acidic (negatively charged), polar; hydrophobic
The wide range of functions carried out by proteins results from…
The diversity of R groups
The primary structure is…
The sequence in which the amino acids are synthesised into the polypeptide.
Hydrogen bonding along the backbone of the protein strand results in…
Regions of secondary structure: Alpha helices, parallel or anti-parallel beta sheets, or turns.
The polypeptide folds into a…
Tertiary structure
This conformation is stabilised by…
Interactions between R groups: hydrophobic interactions; ionic bonds; london dispersion forces; hydrophobic bonds; disulfide bridges.
Disulfide bridges are…
Covalent bonds between R groups containing sulfur.
Quaternary structures exist in proteins with…
Two or more connected polypeptide subunits
Quaternary structure describes the…
Spatial arrangements of the subunits.
A prosthetic group is…
A non-protein unit tightly bound to a protein neccessary for its function.
The ability of haemoglobin to bind oxygen is dependent on…
The non-protein haem group.
Interactions with the R groups can be influenced by…
Temperature and pH
Increasing temperature disrupts the…
Interactions that hold the protein in shape; the protein begins to unfold, eventually becoming denatured.
R groups of amino acids can vary in…
Size, shape, charge, hydrogen bonding capacity and chemical reactivity.
The changes on acidic and basic R groups are affected by…
pH
As pH increases or decreases from the optimum, the normal ionic interactions between charged groups are lost, which gradually changes the…
Conformation of the protein until it becomes denatured.
