Mitochondrial disorders can be caused by mutations in all the following except ____

Mitochondrial disorders primarily arise from mutations that disrupt mitochondrial function and energy production. Mitochondria have their own DNA (mtDNA), which encodes essential proteins required for the proper functioning of the organelle. Mutations in this mitochondrial DNA can directly affect cellular respiration and ATP production, leading to mitochondrial disorders.

Nuclear DNA is also involved in mitochondrial function, as it encodes proteins that are imported into the mitochondria and are critical for their operation. Mutations in nuclear DNA can cause mitochondrial diseases, but they are not classified as mitochondrial disorders in the traditional sense.

On the other hand, genes involved in cell metabolism can influence mitochondrial function since they can affect overall energy metabolism and involve pathways that interact with mitochondrial activities. Therefore, mutations here can lead to complications that compromise mitochondrial function.

Codons in ribosomal RNA (rRNA) do not directly cause mitochondrial disorders because they are primarily involved in the process of protein synthesis rather than encoding proteins directly associated with mitochondrial functions. While ribosomes play a role in translating the information contained in mRNA into proteins, mutations in rRNA codons do not affect the mitochondria or their function directly, making this the exception in the context of causing mitochondrial disorders.