Mitochondria are known as the powerhouses of the cell. They are organelles that act like a digestive system that takes in nutrients, breaks them down, and creates energy-rich molecules for the cell. The biochemical processes of the cell are known as cellular respiration. Many of the reactions involved in cellular respiration happen in the mitochondria. They are the working organelles that keep the cell full of energy.
There are small organelles floating free throughout the cell. Some cells have several thousand mitochondria while others have none. Muscle cells need a lot of energy so they have loads of mitochondria. Neurons (cells that transmit nerve impulses) don’t need as many. If a cell feels it is not getting enough energy to survive, more mitochondria can be created. Sometimes it can grow larger or combine with other mitochondria. It all depends on the needs of the cell.
Structure of Mitochondria
- The mitochondrion is a double-membraned, rod-shaped structure found in both plant and animal cells.
- Its size ranges from 0.5 to 1.0 micrometer in diameter.
- The structure comprises an outer membrane, an inner membrane, and a gel-like material called the matrix.
- The outer membrane and the inner membrane are made of proteins and phospholipid layers separated by the intermembrane space.
- The outer membrane covers the surface of the mitochondrion and has a large number of special proteins known as porins.
- It is freely permeable to ions, nutrient molecules, energy molecules like the ADP and ATP molecules.
Function of Mitochondria
- It can produce energy through the process of oxidative phosphorylation.
- Regulates the metabolic activity of the cell
- Promotes the growth of new cells and cell multiplication
- Helps in detoxifying ammonia in the liver cells
- Plays an important role in apoptosis or programmed cell death
- Responsible for building certain parts of the blood and various hormones like testosterone and oestrogen
- Helps in maintaining an adequate concentration of calcium ions within the compartments of the cell
- It is also involved in various cellular activities like cellular differentiation, cell signaling, cell senescence, controlling the cell cycle, and also in cell growth.