Proteins and enzymes Flashcards
What is the primary structure of a protein?
The sequence of amino acids
What is the secondary structure?
When hydrogen bonds form between peptide links and the chain can coil into alpha helix or fold into beta pleated sheets.
What is the tertiary structure?
The polypeptide chain often coils and folds further
Extra bonds form between different parts of the polypeptide chain which gives the protein a 3d shape.
What factors can affect the shape of the protein
Temperature and pH
As these affect hydrogen boning and Disulfide bonding
How is a Disulfide bond formed?
Cysteine contains a thiol group (-SH-)
thiols can lose their hydrogen atoms and join together to form a Disulfide bond.
Disulfide bonds help to stabilise the tertiary structure
What does it mean if an enzyme’s active site is stereospecific?
The active site will only work on one enantiomer of the substrate
the other enantiomer will not be able to fit onto the active site, so the enzyme cant work on it