Q.46 Give below are two statements : One is labelled as Assertion A and the other is labelled as Reason R
Assertion A : Sum of all the proteins functioning in a given cell is called the proteome : Proteomics is the
systematic characterization of this proteome under a given condition.
Reason R : Expression of genome under a particular condition and its translation is the basis of cell’s
proteome.
In the light of the above statements. choose the most appropriate answer from the options given below :
1. Both A and R are correct and R is the correct explanation of A
2. Both A and R are correct but R is NOT the correct explanation of A
3. A is correct but R is not correct
4. A is not correct but R is correct

Correct Answer: 1. Both A and R are correct and R is the correct explanation of A

The proteome represents all proteins in a cell under specific conditions, proteomics systematically analyzes it, and this arises directly from conditional genome expression followed by translation.

Assertion (A) Analysis

Assertion A is correct. The proteome is the complete set of proteins expressed and functional in a given cell at a particular time/condition, differing from the static genome due to regulation. Proteomics is the large-scale study characterizing proteome composition, modifications, interactions, and functions using MS, 2D gels, etc.

Reason (R) Analysis

Reason R is correct. The cell’s proteome reflects genome expression (transcription to mRNA under condition-specific regulation) plus translation (mRNA to protein), plus PTMs. Unlike fixed DNA, proteome dynamically responds to stimuli via these steps.

Option Breakdown

• Option 1: Both correct, R explains A—True. R directly justifies proteome definition (A) as genome expression/translation outcome.

• Option 2: Both correct, R not explanation—False. R causally defines proteome origin.

• Option 3: A correct, R incorrect—False. R accurate.

• Option 4: A incorrect, R correct—False. A standard definition.

Proteome proteomics genome expression translation defines the dynamic protein complement of cells, with proteomics enabling its study—core concepts linking genomics to function in molecular biology exams.

Proteome Definition

All proteins in a cell/tissue/organism at a given time/condition. Dynamic: changes with development, stress, disease vs. static genome. Includes splice variants, PTMs (phosphorylation, glycosylation). E.g., human cell proteome ~10,000-20,000 proteins expressed.

Proteomics Overview

Systematic analysis:

• Shotgun: MS identifies peptides.

• Quantitative: SILAC, TMT for abundance.

• Spatial: Subcellular localization.
  Applications: biomarkers, drug targets, pathway mapping.​

Genome-to-Proteome Link

R explains A: Proteome = f(transcription + translation + PTMs).

• Condition → TF binding → mRNA levels.

• Translation efficiency → protein levels.

• Degradation/trafficking refines final set.​

Exam Relevance

GATE/NEET tests -omics hierarchy: proteome as post-genomic layer. R causally links to A—key for “explanation” options in assertion-reason.​