Question

Match Column-I with Column-II and select the correct option from the codes given below. Column-I Column-II A. RER (i) Intracellular and extracellular digestion B. SER (ii) Lipid synthesis C. Golgi complex (iii) Protein synthesis and irithe go secretion D. Lysosomes (iv) Moves materials out of the cells (a) \(\mathrm{A}-(\mathrm{iii}), \mathrm{B}-(\mathrm{ii}), \mathrm{C}-(\mathrm{iv}), \mathrm{D}-(\mathrm{i})\) (b) A-(ii), B-(iii), C-(iv), D-(i) \(=\) (c) \(\mathrm{A}\)-(i), B-(iii), C-(ii), D-(iv) (d) A-(iv), B-(ii), C-(iii), D-(i)

Short answer

The correct option is (a) A-(iii), B-(ii), C-(iv), D-(i).

Step-by-step solution

Understanding the Function of RER

RER stands for Rough Endoplasmic Reticulum. It is involved in the synthesis of proteins. Thus, A should be matched with 'Protein synthesis'.

Understanding the Function of SER

SER stands for Smooth Endoplasmic Reticulum. It is involved in lipid synthesis, detoxification, and metabolism of carbohydrates. Hence, B should be matched with 'Lipid synthesis'.

Understanding the Function of Golgi Complex

The Golgi complex is responsible for modifying, sorting, and packaging proteins and lipids for secretion or delivery to other parts of the cell. Therefore, C should be matched with the option that refers to movement of materials out of the cell.

Understanding the Function of Lysosomes

Lysosomes contain digestive enzymes and are involved in intracellular digestion (breaking down waste materials and cellular debris). Thus, D should be matched with 'Intracellular and extracellular digestion'.

Matching Functions to Options

With the known functions: A is for 'Protein synthesis', B is for 'Lipid synthesis', C moves 'Materials out of the cells', and D is for 'Digestion'. The option that correctly matches all these is (a) A-(iii), B-(ii), C-(iv), D-(i).

Key concepts

Rough Endoplasmic Reticulum (RER)

The Rough Endoplasmic Reticulum (RER) is a critical part of cell function, recognized by the presence of ribosomes on its surface, giving it a 'rough' appearance. Think of the RER as a factory where proteins are made.

These proteins are essential for various cellular processes like repairing damage or directing chemical processes. As the ribosomes build proteins, they thread them into the RER's interior, where they are folded and modified. Importantly, many of these proteins are destined to be part of the cell membrane, or they are exported out of the cell as enzymes or hormones.

Role in Protein Quality Control

Additionally, the RER plays a critical role in quality control, ensuring that only properly formed proteins reach their final destinations. If errors in protein structure are detected, they are typically targeted for destruction and recycled within the cell. This helps prevent the accumulation of faulty proteins that could potentially harm the cell or lead to diseases.

Smooth Endoplasmic Reticulum (SER)

While the Rough Endoplasmic Reticulum is busy making proteins, the Smooth Endoplasmic Reticulum (SER) focuses on producing lipids, which are crucial components of cellular membranes and serve as energy storage molecules. Unlike the RER, the SER lacks ribosomes, giving it a 'smooth' appearance.

The SER also detoxifies potentially harmful substances and plays a role in carbohydrate metabolism. For instance, in liver cells, the SER helps detoxify drugs and poisons.

Regulation of Calcium Levels

Another vital function of the SER is the regulation of calcium levels within the cell. In muscle cells, for example, it stores calcium ions and releases them to trigger muscle contractions. This shows how the SER's diverse functions are integral to proper cell function and the organism's overall well-being.

Golgi Complex

The Golgi Complex, often called the 'post office' of the cell, receives proteins and lipids from the endoplasmic reticulum and modifies them. After these molecules are modified, the Golgi sorts and packages them into vesicles.

Some vesicles transport their contents to other areas of the cell, whereas others merge with the cell membrane to release contents outside the cell, in a process known as secretion.

Formation of Lysosomes and Transport Vesicles

Furthermore, the Golgi Complex is involved in forming lysosomes, which are vesicles filled with enzymes that digest cellular waste. By routing materials to their proper destinations, the Golgi complex maintains the cell's internal organization and contributes significantly to the trafficking of cellular components.

Lysosomes

Lysosomes are like the 'recycling center' of the cell. They are filled with powerful enzymes that break down waste materials and cellular debris.

When a cell needs to dispose of damaged organelles or engulfed viruses or bacteria, lysosomes fuse with these items and use their enzymes to break them down into small, manageable pieces that are then either expelled from the cell or reused within it.

Role in Apoptosis

Moreover, lysosomes also play a part in apoptosis, or programmed cell death, which is a natural process to eliminate cells that are no longer needed or are functioning improperly. Hence, lysosomes, by managing waste and participating in cell renewal, underpin the cell’s health and maintenance.