Answer: Through extensive bonding
Step-by-step explanation:
Oxidation of two cysteine gives disulphide bonds. They are covalent in nature. Given as;
R-CH2-SH + R'-CH2 +02 = R-CH2-S-S-CH2-R' + H202
They are the stabilizing force behind protein folding the endoplasmic reticulum. Proteins being the backbone of our genetic constitution require disulphide bonding to stabilize the peptide molecules and the extent and number of this bonding determines the Resistance of the protein molecule to extreme conditions e.g extreme heat which denatures proteins and elasticity as well.