Question

Which of the following cellular organelle/compartment is composed of single membrane and participates in scavenging ROS?

• A. Vacuole
• B. Peroxisome
• C. Golgi vesicles
• D. Plasma membrane

Hint:

Whenever you see "Catalase" or "Hydrogen Peroxide metabolism," the answer is almost always Peroxisomes.
Also, remember that Peroxisomes, Lysosomes, and Vacuoles are the major single-membrane organelles, while Mitochondria, Chloroplasts, and the Nucleus are double-membrane bound.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question requires identifying an organelle that satisfies two conditions:
1. It must be bound by a single membrane.
2. It must play a functional role in scavenging Reactive Oxygen Species (ROS) like hydrogen peroxide (\( H_2O_2 \)).
Detailed Explanation:

• Peroxisome Structure:
Peroxisomes are small, spherical organelles found in almost all eukaryotic cells.
They are characterized by being bound by a single lipid bilayer membrane.
They often contain a crystalline core of enzymes.

• ROS Scavenging Function:
Peroxisomes are the primary site for the metabolism of reactive oxygen species.
They contain the enzyme Catalase, which facilitates the breakdown of hydrogen peroxide (\( H_2O_2 \)) into water and oxygen.
\[ 2H_2O_2 \rightarrow 2H_2O + O_2 \]
By doing so, they protect the rest of the cell from oxidative damage caused by byproduct peroxides generated during fatty acid beta-oxidation and photorespiration.

• Analyzing other options:
Vacuole: Single-membrane bound (tonoplast), but primarily involved in storage and turgor pressure, not primary ROS scavenging.
Golgi vesicles: Single-membrane bound, but involved in protein modification and transport.
Plasma membrane: A single bilayer that encloses the cell, but its primary function is transport and signaling, not intracellular enzymatic ROS detoxification.

Step 3: Final Answer:
The peroxisome is the single-membrane organelle dedicated to scavenging ROS via enzymes like catalase.