A) Not all genes are translated,so the number of expressed proteins is lower than the number of protein coding genes.
B) Not all genes are transcribed,so the number of expressed proteins is lower than the number of protein coding genes.
C) Alternative splicing is very common and increases the diversity of expressed proteins so the number of expressed proteins is higher than the number of protein coding genes.
D) Alternative splicing is very common and decreases the diversity of expressed proteins so the number of expressed proteins is lower than the number of protein coding genes.
E) Protein turnover is rapid and decreases the diversity of expressed proteins so the number of expressed proteins is lower than the number of protein coding genes.

A) 500
B) 5,000
C) 25,000
D) 50,000
E) 500,000

A) It increases the precision of the analysis.
B) It is used to break apart large protein complexes prior to mass spectrometry.
C) It is the site of undesirable reactions that can reduce accuracy.
D) It is the primary site of ionization.
E) It rejoins peptide fragments into their original configuration.