Problem 29 - Objective Biology for NEET

Question

The correct equation of photosynthesis is (a) \(\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O} \stackrel{\text { Light }}{\longrightarrow}\left[\mathrm{CH}_{2} \mathrm{O}\right]+\mathrm{O}_{2}\) (b) \(2 \mathrm{H}_{2} \mathrm{~A}+\mathrm{CO}_{2} \stackrel{\text { Light }}{\longrightarrow} 2 \mathrm{~A}+\mathrm{CH}_{2} \mathrm{O}+\mathrm{H}_{2} \mathrm{O}\) (c) \(6 \mathrm{CO}_{2}+12 \mathrm{H}_{2} \mathrm{O} \stackrel{\text { Light }}{\longrightarrow} \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}+6 \mathrm{H}_{2} \mathrm{O}+6 \mathrm{O}_{2}\) (d) \(6 \mathrm{CO}_{2}+6 \mathrm{H}_{2} \mathrm{O}\) Light \(\longrightarrow \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}+6 \mathrm{O}_{2}\)

Step-by-Step Solution

Answer

The correct equation for photosynthesis is option (d): \(6 \mathrm{CO}_{2}+6 \mathrm{H}_{2} \mathrm{O}\) Light \(\longrightarrow \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}+6 \mathrm{O}_{2}\)

Step 1: Understanding the process of Photosynthesis

The photosynthesis process is the way that plants produce their food with the help of light. The process primarily involves the conversion of carbon dioxide (CO2) and water (H2O) into glucose (C6H12O6) and oxygen (O2). The energy for this process is derived from light, often sunlight.

Step 2: Breakdown the given options

Let's take a look at the each of the options given: (a) doesn't match the requirement because it lacks the formation of glucose. (b) consists of superfluous components not involved in photosynthesis. (c) seems accurate but it has an excess of water molecules. (d) seems to be matching our understanding but we need to further verify.

Step 3: Verify the Balanced Chemical Equation for Photosynthesis

The balanced chemical reaction for photosynthesis should suggest that one molecule of glucose (C6H12O6) is formed using six molecules of carbon dioxide (CO2) and six molecules of water (H2O), and in this process, six molecules of oxygen (O2) are created as a by-product. This accurately matches option (d).

Key Concepts

Glucose Formation

Photosynthesis is a remarkable biological process by which plants produce glucose. Glucose, a type of sugar, serves as the basic energy source for plants and other organisms. The light energy absorbed by chlorophyll during photosynthesis powers the reaction that forms glucose. The balanced equation for this transformation is:

• Six molecules of carbon dioxide (CO2)
• Six molecules of water (H2O)
• Produce one molecule of glucose (C6H12O6)
• And six molecules of oxygen (O2)

Glucose is vital because it stores energy that plants can use for growth and reproduction. It also serves as the starting point for other organic molecules essential for life.

Carbon Dioxide Conversion

Carbon dioxide conversion is a crucial part of photosynthesis. In the process, plants take carbon dioxide from the atmosphere and convert it into organic compounds. This transformation takes place in a part of the chloroplast known as the Calvin Cycle. During this cycle:

• Carbon dioxide molecules are fixed into a stable intermediate.
• Energy from ATP and NADPH, produced during the light-dependent reactions, helps synthesize glucose.

This conversion is significant not only for generating glucose but also for reducing atmospheric carbon dioxide levels, which helps mitigate climate change.

Oxygen Production

Oxygen production during photosynthesis is a critical by-product of this process. As plants convert carbon dioxide and water into glucose, they also release oxygen into the atmosphere. This oxygen is produced during the light-dependent reactions of photosynthesis. Here’s how it happens:

• Water molecules are split through a process known as photolysis.
• This splitting releases oxygen gas as a by-product.

The oxygen we breathe is mainly a result of photosynthesis, making plants vital for life on Earth.

Balanced Chemical Equation

A balanced chemical equation is essential to illustrating the photosynthesis process accurately. It ensures that the number of atoms for each element is the same on both sides of the equation. This is crucial because matter is neither created nor destroyed in chemical reactions.The balanced equation for photosynthesis is:\[6 \mathrm{CO}_{2} + 6 \mathrm{H}_{2} \mathrm{O} + ext{light energy} \rightarrow \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6} + 6 \mathrm{O}_{2}\]This equation reveals the stoichiometry of photosynthesis:

• Six carbon dioxide molecules are consumed.
• Six water molecules react.
• One glucose molecule is produced.
• Six oxygen molecules are released.

Understanding the balanced equation helps us appreciate the precise nature of this transformative biochemical process.