Fill in the table below by naming one metal for each case: haemoglobin in oxygen transport, transmission of nerve impulses, enzyme cofactor.
Enzymes are a distinctive class of protein molecules that catalyse biochemical reactions. Explain briefly the mechanism by which an enzyme breaks down a substrate molecule.
Disulfide bonds help stabilise some proteins such as the keratin in human hair. At which level of protein structure (primary, secondary, tertiary) are disulfide bonds formed?
Use a functional group in cysteine, $\text{H}_2\text{NCH(CH}_2\text{SH)CO}_2\text{H}$, to show how disulfide bonds are formed.
What kind of chemical reaction is this?
The NMR spectrum of cysteine, $\text{H}_2\text{NCH(CH}_2\text{SH)CO}_2\text{H}$, gives five absorptions. After a solution of cysteine is shaken with a few drops of $\text{D}_2\text{O}$, the NMR spectrum shows only two absorptions, E and F. Identify the two types of protons responsible for the absorptions E and F.
State and explain the splitting patterns of the absorptions E and F.