Define cristae of a mitochondria

Mitochondria – The Powerhouse of the Cell

• Mitochondria are double-membrane-bound organelles found only in eukaryotic cells.
• They generate the chemical energy required for various biochemical reactions.
• This energy is stored in the form of adenosine triphosphate (ATP), hence mitochondria are known as the “powerhouse of the cell.”
• Mitochondria are semi-autonomous, as they contain their own DNA and ribosomes, enabling them to produce some of their own proteins.
• Their size typically ranges from 0.75 to 3 μm².

Function of Mitochondria

• The main role of the mitochondrial membrane system is to produce ATP.
• ATP molecules contain high-energy phosphate bonds that act as the primary energy currency of the cell.
• The number of mitochondria in a cell depends on energy requirements. For example, muscle cells contain a large number of mitochondria to meet high energy demands.

Structure of Mitochondria

Mitochondria have a double-membrane system dividing them into five distinct parts:

1. Outer mitochondrial membrane
2. Intermembrane space
3. Inner mitochondrial membrane
4. Cristae space
5. Matrix

Cristae

• Cristae are folds or invaginations of the inner mitochondrial membrane.
• They increase the surface area, enhancing ATP production through the chemiosmotic process.
• Cristae are studded with F₁ particles (oxysomes), which play a direct role in ATP synthesis.

Note

• Cristae are crucial for efficient energy production.
• Disorders linked to cristae dysfunction include amyotrophic lateral sclerosis (ALS), Alzheimer’s disease, and Parkinson’s disease.