All of the following are post-translational modifications except A. Elongation B. Phosphorylation C. Proteolytic cleavage D. Glycosylation A. Elongation

Elongation

Explanation:

Elongation (in the context of DNA) is not a form of post translational modification. It is basically an increase in the length of a particular growing nucleotide chain during either replication, translation or transcription. Post translation modifications are basically changes that are most of the times chemical that can take place in a protein after translation and some of these occur to activate or to cleave some specific regions. Examples including phosphorylation, glycosylation (conjugation of carbohydrate by enzymes) etc

b is the correct answer