Protein synthesis is a function of:

Appeared in: AIIMS BHOPAL NO- 2018( Shift-2nd)

Explanation

The Rough Endoplasmic Reticulum (RER) is named for its 'rough' appearance, which is due to the presence of ribosomes attached to its surface.
These attached ribosomes are the primary sites for protein synthesis (translation), where genetic information from mRNA is used to build polypeptide chains.
The RER is especially prominent in cells that specialize in secreting proteins, such as pancreatic cells that produce insulin or plasma cells that produce antibodies.

Option A: The Smooth Endoplasmic Reticulum (SER) lacks ribosomes and is therefore not involved in protein synthesis.
Option C: Mitochondria are responsible for cellular respiration and energy (ATP) production, not protein synthesis.
Option D: The Golgi apparatus is involved in modifying, sorting, and packaging proteins after they are synthesized, but it is not the site of synthesis itself.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Functions of cellular organelles as background academic context rather than a clinical decision trigger.
A solid understanding of organelle function is fundamental to understanding pathophysiology. For instance, certain genetic disorders involve the misfolding of proteins within the RER, leading to diseases like cystic fibrosis, where the CFTR protein is degraded instead of being transported to the cell membrane.
What if? If a patient has a disease affecting mitochondrial function (a mitochondriopathy), the primary clinical manifestation would be severe fatigue and muscle weakness due to a lack of ATP, not impaired protein production.

How to Approach the Question

First, identify the key process in the question stem: 'protein synthesis'.
Next, systematically review the function of each organelle listed in the options.
Recall that 'ribosomes' are the cellular machinery responsible for protein synthesis.
Connect the presence of ribosomes to the 'rough' in Rough Endoplasmic Reticulum, which is named for the ribosomes studded on its surface.
Eliminate the other options based on their distinct primary functions: Smooth ER (lipids/detox), Mitochondria (energy/ATP), and Golgi apparatus (packaging/sorting).

Concept Tested & Keywords

QCtBPFk8XcJiQSYa9cxx79

E6 Physiology Guyton 4SAE Part 1 p. 47-49

Ross & Willson - Anatomy and Physiology p. 56-63

Practise the full AIIMS BHOPAL NO- 2018( Shift-2nd)

Attempt every question from this paper in a timed mock, then review the full solution for each one.