BIOL 1207 Chapter : Bio 1208 Lab Report
Document Summary
Ribosomes are highly preserved, large ribonucleoprotein (rnp) particles. In yeast, they consist of a large 60s subunit and a small 40s subunit that perform protein synthesis and contain one copy each of four ribosomal rnas. They are produced in two separate transcripts and encoded within the rdna repeat appearing as hundreds of copies on chromosome 12 and 79 different ribosomal proteins (r-proteins), which are encoded by 137 different genes dispersed throughout the genome. 59 of the 137 different genes are duplicated. The 60s subunit contains 46 proteins and three rna molecules: 25s. Rna of 3392 nt, hydrogen bonded to the 5. 8s rna of 158 nt and associated with the 5s. All yeast ribosomal proteins have a mammalian homolog. In a yeast cell that is growing at a fast rate, 60% of total transcription is devoted strictly to ribosomal. Rna, and 50% of rna polymerase ii transcription and 90% of mrna splicing are devoted to the assembly of mrnas for r-proteins.
