Mitochondria

The mitochondria are membrane-bound organelles found in the cytoplasm of eukaryotic cells. They are often referred to as the powerhouse of the cell due to their role in producing adenosine triphosphate (ATP), the primary energy currency of the cell.

Structure of Mitochondria

The structure of a mitochondrion consists of an outer membrane, an inner membrane, intermembrane space, and matrix. The inner membrane is highly folded into structures called cristae, which increase the surface area for ATP production. The matrix contains enzymes necessary for the citric acid cycle (Krebs cycle) and fatty acid oxidation.

Function of Mitochondria

The primary function of mitochondria is to generate ATP through the process of cellular respiration. This involves a series of complex biochemical reactions that occur in the inner mitochondrial membrane and the matrix. Mitochondria also play a role in regulating cellular metabolism, apoptosis (programmed cell death), and calcium storage.

Mitochondrial DNA

One unique feature of mitochondria is that they contain their own DNA, known as mitochondrial DNA (mtDNA). This DNA is separate from the nuclear DNA found in the cell's nucleus and is inherited maternally. The presence of mtDNA supports the endosymbiotic theory, which suggests that mitochondria evolved from ancient symbiotic bacteria that were engulfed by ancestral eukaryotic cells.

Study Guide

1. What is the primary function of mitochondria?
2. Describe the structure of a mitochondrion.
3. Explain the role of mitochondria in cellular respiration.
4. What is mitochondrial DNA and how is it inherited?
5. Discuss the significance of mitochondria in the context of the endosymbiotic theory.