Energy Conversion in a Cell




Introduction:
In a cell, energy is converted from one form to another in order to carry out various biological processes. The primary source of energy in cells is chemical energy, which is stored in molecules such as glucose. This chemical energy is then converted into other forms of energy to perform specific functions within the cell.

Answer:
The correct answer is option 'B' - Chemical energy into electrical energy. This conversion occurs in specialized structures called mitochondria, which are present in most eukaryotic cells.

Explanation:
Here is a detailed explanation of this energy conversion process:

1. Chemical Energy in Glucose:
Glucose is a type of sugar that serves as a major source of chemical energy in cells. During cellular respiration, glucose is broken down in the presence of oxygen to produce energy-rich molecules called ATP (adenosine triphosphate). This process occurs in the mitochondria.

2. Mitochondria and ATP Production:
The mitochondria are often referred to as the "powerhouses" of the cell because they generate a large amount of ATP. Within the mitochondria, glucose undergoes a series of chemical reactions known as cellular respiration. This process involves the breakdown of glucose molecules into smaller units, releasing energy in the form of ATP.

3. Electron Transport Chain:
The final stage of cellular respiration occurs in the inner membrane of the mitochondria, where electrons are transported through a series of protein complexes known as the electron transport chain. As electrons pass through the chain, their energy is gradually released, and this energy is used to pump protons (H+) across the membrane, creating an electrochemical gradient.

4. ATP Synthesis:
The electrochemical gradient created by the electron transport chain drives the synthesis of ATP through a process called chemiosmosis. The protons flow back across the membrane through a protein complex called ATP synthase, which harnesses the energy from this flow to produce ATP molecules.

5. Electrical Energy in ATP:
ATP is a molecule that stores energy in its phosphate bonds. When one of these bonds is broken, ATP releases the stored energy, which can be used to perform various cellular functions. This release of energy involves the movement of charged particles, primarily protons and electrons, which can be considered as electrical energy.

Therefore, in a cell, chemical energy stored in glucose is converted into electrical energy in the form of ATP. This electrical energy is then utilized for various cellular processes, such as muscle contraction, active transport, and synthesis of macromolecules.

Overall, option 'B' - Chemical energy into electrical energy, is the correct answer as it accurately describes the energy conversion that takes place in a cell.