Problem 75 - Objective Biology for NEET

Question

A polysome is a chained structure of which organelle? (a) Lysosome (b) Mesosome (c) Ribosome (d) All of these

Step-by-Step Solution

Answer

The polysome is a chained structure of Ribosome. So, the correct answer is (c) Ribosome.

Step 1: Understanding the Term

A polysome, also known as a polyribosome, is a cluster of ribosomes bonded together. This term is introduced or explained in the lesson of cell biology. So, recognize the term, and recall the related concept from the teachings.

Step 2: Identify the Correct Choice

Now, the list of choices includes: Lysosome, Mesosome, Ribosome and All of these. By remembering correctly from learning, a polysome is related to Ribosomes. Thus, the answer must be Ribosome (choice c).

Key Concepts

Polysome

A polysome, or polyribosome, is a fascinating structure in the world of cell biology. Imagine a string of pearls, but each pearl is a ribosome.
They are all working together on a single strand of mRNA. The purpose of a polysome is to optimize the process of protein synthesis.

• Polysomes enhance the speed and efficiency of protein production inside cells.
• Multiple ribosomes can read a single mRNA strand simultaneously, translating it into a polypeptide chain.

This setup allows cells to rapidly synthesize large amounts of a particular protein, which is essential for cellular functions and responses. Therefore, polysomes are integral to the understanding of cellular machinery and its ability to execute complex biological processes swiftly.

Ribosome

Ribosomes are like tiny, tireless factories, manufacturing proteins that are essential for life. Found in every living cell, their primary function is protein synthesis.
Ribosomes do this by translating genetic information from mRNA into a sequence of amino acids, forming a protein.
Each ribosome consists of two subunits:

• The large subunit, where peptide bonds are formed.
• The small subunit, which reads the RNA.

These subunits are composed of ribosomal RNA (rRNA) and proteins. Ribosomes can be found floating freely in the cytoplasm or attached to the endoplasmic reticulum, where they aid in the production of proteins that have specific destinations in the cell or are meant to be exported out of the cell.

Organelles

Organelles are the miniature organs of the cell, each performing a unique and crucial role in maintaining cellular function. Think of them as the vital compartments or structures within a cell, each with specific duties:

• Nucleus: Acts as the control center of the cell, containing genetic material (DNA).
• Mitochondria: Known as the powerhouse of the cell, it's where energy production occurs.
• Endoplasmic Reticulum (ER): Rough ER is studded with ribosomes and involved in protein synthesis, while Smooth ER is crucial for lipid synthesis and detoxification.
• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for storage or transport out of the cell.

These organelles work in harmony to ensure that the cell functions properly, much like the teamwork between ribosomes in a polysome. Understanding organelles helps us grasp how complex and dynamic life is at a cellular level.