Mítókondríunnar

Mítókondríunnar are cellular organelles found in eukaryotic cells. They are often referred to as the "powerhouses" of the cell because their primary function is to generate adenosine triphosphate (ATP), the main energy currency of the cell. This process is known as cellular respiration. Mítókondríunnar have a unique double membrane structure. The outer membrane is smooth, while the inner membrane is highly folded into structures called cristae. These folds increase the surface area of the inner membrane, which is crucial for the efficient production of ATP.

Within the inner membrane are the enzymes and protein complexes involved in the electron transport chain and oxidative phosphorylation, the final stages of cellular respiration. Mítókondríunnar also contain their own DNA, known as mitochondrial DNA (mtDNA), and ribosomes, allowing them to synthesize some of their own proteins. This characteristic has led to the endosymbiotic theory, which proposes that mitochondria originated from free-living bacteria that were engulfed by an ancestral eukaryotic cell.

Besides energy production, mítókondríunnar play roles in other cellular processes, including calcium homeostasis, programmed cell death (apoptosis), and the synthesis of certain steroids and heme. Dysfunction of mítókondríunnar is implicated in a variety of human diseases, collectively known as mitochondrial diseases. These conditions can affect organs with high energy demands, such as the brain, heart, and muscles.