which of the following cellular organelles is responsible for realising the energy contained in food
The cellular organelle responsible for releasing the energy contained in food is called the mitochondria.
The cellular organelle responsible for releasing the energy contained in food is the mitochondria. It is often referred to as the "powerhouse" of the cell because it generates most of the cell's supply of adenosine triphosphate (ATP), which is the energy currency of the cell.
To understand how the mitochondria releases energy, you can look at the process of cellular respiration. Cellular respiration is a series of metabolic reactions that take place within the mitochondria. It involves the breakdown of glucose (which comes from food) in the presence of oxygen to produce ATP.
Here's a step-by-step explanation of how the mitochondria releases energy through cellular respiration:
1. Glucose, a simple sugar, enters the cell through various transport mechanisms. It is derived from the food we eat.
2. In the cytoplasm of the cell, glucose is broken down into smaller molecules during a process called glycolysis. This process does not require oxygen and takes place outside the mitochondria.
3. The resulting molecules from glycolysis enter the mitochondria. In the mitochondrial matrix, these molecules undergo further breakdown through a series of chemical reactions known as the Krebs cycle (also called the citric acid cycle or TCA cycle). This process generates a small amount of ATP and electron carrier molecules (NADH and FADH2).
4. The electron carrier molecules produced in the Krebs cycle transport high-energy electrons to the inner membrane of the mitochondria, where the electron transport chain is located.
5. In the electron transport chain, the high-energy electrons from NADH and FADH2 are passed along a series of protein complexes, generating energy in the form of ATP. This process is coupled with the transfer of protons (H+) across the inner mitochondrial membrane, creating an electrochemical gradient.
6. The electrochemical gradient drives ATP synthesis through a specialized protein called ATP synthase, located in the inner mitochondrial membrane. This enzyme allows the protons to flow back into the matrix, facilitating the production of ATP from adenosine diphosphate (ADP) and inorganic phosphate (Pi).
In summary, the mitochondria is responsible for releasing the energy contained in food through cellular respiration, specifically during the Krebs cycle and electron transport chain. It converts glucose into ATP, providing the cell with the energy it needs to perform various functions.