L-isomer of tetrose $$\mathrm{X}\left(\mathrm{C}_{4} \mathrm{H}_{8} \mathrm{O}_{4}\right)$$ gives positive Schiff's test and has two chiral carbons. On acetylation, '$$\mathrm{X}$$' yields triacetate. '$$\mathrm{X}$$' also undergoes following reactions

'$$\mathrm{X}$$' is

The one that does not stabilize 2$$^\circ$$ and 3$$^\circ$$ structures of proteins is

Match List I with List II

Choose the correct answer from the options given below:

Sulphur (S) containing amino acids from the following are:

(a) isoleucine (b) cysteine (c) lysine (d) methionine (e) glutamic acid