| Comments |
P.258 2nd paragraph: "Almost two-thirds (24 out of 37) of the mitochondrial genes specify a functional noncoding RNA as their final product. There are 22 tRNA genes, one for each of the 22 types of mitochondrial tRNA. In addition, two rRNA genes are dedicated
to making 16S rRNA and 12S rRNA (components of the large and small
subunits, respectively, of mitochondrial ribosomes). The remaining 13 genes encode polypeptides, which are synthesized on mitochondrial ribosomes. These 13 polypeptides form part of the mitochondrial respiratory complexes, the
enzymes of oxidative phosphorylation that are engaged in the production of ATP. However, the great majority of the polypeptides that make up the mitochondrial oxidative phosphorylation system plus all other mitochondrial proteins are encoded by nuclear genes (Table 9.1). These proteins are translated on cytoplasmic ribosomes before being imported into the mitochondria." See note beneath table |