Explain why diseases caused by mutations in mitochondrial dna quizlet
Explain why diseases caused by mutations in mitochondrial dna quizlet Mutations in mitochondrial DNA (mtDNA) can lead to a variety of diseases that often have profound and diverse effects on the human body. Unlike nuclear DNA, which is inherited from both parents, mitochondrial DNA is inherited exclusively from the mother. This unique inheritance pattern, coupled with the essential role mitochondria play in energy production, explains why mutations in mtDNA can cause specific and often severe diseases.
Explain why diseases caused by mutations in mitochondrial dna quizlet Mitochondria are often referred to as the powerhouses of the cell because they generate most of the cellular energy in the form of adenosine triphosphate (ATP). This energy is critical for the functioning of high-energy-demand tissues such as the brain, muscles, heart, and liver. When mutations occur in mitochondrial DNA, they can impair the mitochondria’s ability to produce ATP efficiently. This energy deficiency manifests in tissues with high energy demands, leading to symptoms such as muscle weakness, neurological deficits, and cardiac problems.
One key reason why diseases caused by mitochondrial DNA mutations are so varied is the heteroplasmic nature of mtDNA. Unlike nuclear DNA, where each cell typically contains two copies of each gene, cells can contain hundreds to thousands of mitochondria, each with multiple copies of mtDNA. Mutations in some copies may not affect function if the majority of mtDNA copies are normal, but as the proportion of mutated mtDNA increases—a condition known as heteroplasmy—the cell’s energy production diminishes. This variability explains why individuals with the same mitochondrial mutation can experience different symptoms and severity levels. Explain why diseases caused by mutations in mitochondrial dna quizlet
Furthermore, mitochondrial DNA is more susceptible to mutations than nuclear DNA. This increased mutation rate is due to the proximity of mtDNA to reactive oxygen species (ROS) generated during respiration, and the relatively limited repair mechanisms available for mitochondrial DNA. As a result, mutations can accumulate more rapidly, leading to mitochondrial diseases that may manifest at any age, from infancy to adulthood. Explain why diseases caused by mutations in mitochondrial dna quizlet
The inheritance pattern of mitochondrial diseases is also unique. Since mitochondria are inherited maternally, these diseases are passed down from mothers to all their children, but only daughters can pass the mutations on to subsequent generations. This maternal inheritance pattern helps explain why certain mitochondrial diseases tend to run through families in a specific maternal lineage. Explain why diseases caused by mutations in mitochondrial dna quizlet
Mitochondrial DNA mutations can cause a range of diseases, including Leber’s Hereditary Optic Neuropathy (LHON), which leads to sudden vision loss, and mitochondrial myopathies, characterized by muscle weakness and exercise intolerance. Some mitochondrial disorders affect multiple organ systems, such as MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) and Kearns-Sayre syndrome, which involve neurological, muscular, and cardiac symptoms.
In conclusion, mutations in mitochondrial DNA cause diseases primarily because they impair the mitochondria’s ability to produce energy efficiently, especially in tissues with high energy demands. The unique inheritance pattern, susceptibility to mutations, and heteroplasmy contribute to the diverse manifestations of mitochondrial diseases, making them a complex and critical area of study in genetic medicine. Explain why diseases caused by mutations in mitochondrial dna quizlet
