30. Mitochondrial protein synthesis, mitochondrial genome

Last updated on November 19, 2018 at 17:16


  • Mitochondria contain their own genome and protein synthetic machinery
  • Many of the proteins mitochondria use are synthesized there, but some are imported from the cytosol
  • No mitochondrial proteins are exported
  • Each mitochondrion can contain many copies of the mitochondrial DNA.
  • mtDNA contains only 17 000 base pairs, which code for just 37 genes, is a double stranded ring and contains no histones or introns.
  • mtDNA codes for some of the subunits of the proteins of the respiratory chain. The rest comes from nuclear DNA.
  • The genetic code of mitochondrial DNA is slightly different from the universal genetic code
  • 99.9% of mtDNA is inherited from the mother, only 0.01% from the father

Another short topic

There’s not much more to say than what’s written in the summary.

The 37 genes codes for tRNAs, rRNA and a few subunits of the proteins in the respiratory chain. Most of the subunits of mitochondrial proteins are encoded by nuclear DNA, synthesized in cytosol, and then imported into the mitochondria.

mtDNA is replicated by mtDNA polymerase, which has a 10x lower accuracy than DNA polymerase.

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29. Regulation of gene expression

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31. Hormones

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