Question

\(\mathrm{Mg}\) is an important component of which biomolecule occurring extensively in living world? (a) Chlorophyll (b) Haemoglobin (c) ATP (d) Florigen

Short answer

Magnesium is a component of chlorophyll.

Step-by-step solution

Identify the Role of Magnesium

To tackle this question, we need to identify which biomolecules extensively use magnesium (Mg) in their structure or function. We know magnesium plays a crucial role in chlorophyll, the molecule involved in photosynthesis in plants, where it acts as the central atom in the chlorophyll molecule.

Consider Component Structures

Let's consider the structure of each option. - **Chlorophyll**: Contains Mg as a central atom. - **Haemoglobin**: Contains iron (Fe) instead of Mg. - **ATP**: Does not structurally incorporate Mg, though it interacts with it. - **Florigen**: Not a widely accepted biomolecule and does not structurally require Mg.

Match Biomolecule to Magnesium

From the analysis, chlorophyll is the only biomolecule among the options provided that structurally incorporates magnesium as its central atom, essential for its function in photosynthesis.

Key concepts

Chlorophyll structure

Chlorophyll is a fascinating and vital biomolecule found primarily in the leaves of plants, as well as algae and cyanobacteria. It is the pigment responsible for the green color associated with most plants. However, its significance goes far beyond aesthetics. Chlorophyll plays an essential role in the process of photosynthesis, enabling plants to convert sunlight into chemical energy.
One of the unique structural features of chlorophyll is its porphyrin ring. At the heart of this ring is a magnesium ion ( Mg^{2+} ), which is crucial for chlorophyll's functionality. The porphyrin ring is a large, flat molecule that acts like an antenna to absorb sunlight. The absorbed light excites the electrons within the magnesium ion, enabling energy transfer and initiating the photosynthesis chemical reactions.
In the structure of chlorophyll, the porphyrin ring is connected to a long phytol tail. This tail helps anchor the chlorophyll molecule into the thylakoid membrane of chloroplasts, where photosynthesis occurs. The intricate structure of chlorophyll, with its specialized components, highlights its efficiency in capturing and transforming light energy.

Magnesium role in photosynthesis

Magnesium is a key player in the world of photosynthesis, primarily because it sits at the center of the chlorophyll molecule. This central position is not arbitrary; magnesium's presence is vital for the absorption of light energy, which is the first critical step of photosynthesis.
Magnesium's role begins when sunlight strikes the chlorophyll molecules within the chloroplasts. Here’s why magnesium is so important:

• It helps stabilize the structure of chlorophyll, ensuring it forms the right configuration to absorb light efficiently.
• The energy from light excites the magnesium ion's electrons, starting a cascade of reactions that convert light energy into chemical energy.
• Magnesium also helps in transmitting energy captured from sunlight to other plant cell components to synthesize sugars from carbon dioxide and water.

The presence of magnesium in chlorophyll is so vital that without it, the efficiency of photosynthesis would be severely impacted, significantly affecting plant growth and oxygen production.

Biomolecule components

Biomolecules are the building blocks of life, consisting of specific elements and structures, each tailored to perform distinct functions essential for life. Let's explore some critical components of biomolecules:
The four main classes of biomolecules are carbohydrates, lipids, proteins, and nucleic acids. Each of these classes contains unique components and serves specific roles in biological systems. For instance:

• **Carbohydrates**: Comprised mainly of carbon, hydrogen, and oxygen, they serve as a primary energy source.
• **Lipids**: Mostly made up of carbon, hydrogen, and a small amount of oxygen, serving as long-term energy stores and composing cellular membranes.
• **Proteins**: Consist of amino acids linked by peptide bonds, containing elements like carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur, functioning as enzymes, hormones, and structural components.
• **Nucleic acids**: DNA and RNA are crucial for genetic information storage and transfer, primarily composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus.

These biomolecules are organized into complex structures, where elements like magnesium, iron, and calcium come into play, each indispensable in specific biological reactions and structural integrity. For example, as we've seen, magnesium is central in chlorophyll, playing a crucial role in photosynthesis, while iron is vital in hemoglobin for oxygen transport.