A chloroplast is the organelle that carries out photosynthesis and starch grain formation. It is a chlorophyll-containing organelle in plants that is the site of photosynthesis.
These make up some 128 genes which include:
- duplicate genes encoding each of the four subunits (23S, 16S, 4.5S, and 5S) of the ribosomal RNA (rRNA) used by the chloroplast
- 37 genes encoding all the transfer RNA (tRNA) molecules used for translation within the chloroplast.
Some of these are represented in the figure by black bars.
4 genes encoding some of the subunits of the RNA polymerase used for transcription within the chloroplast (the blue ones)
a gene encoding the large subunit of the enzyme ribulose bisphosphate carboxylase oxygenase (RUBISCO)
9 genes for components of photosystems I and II
6 genes encoding parts of the chloroplast ATP synthase
genes for 19 of the ~60 proteins used to construct the chloroplast ribosome