Molekulaar- ja rakubioloogia konspekt
replaced with a centromere-specific variant, CENP-A in humans.
5. Peamine erinevu prokarüootse ja eukarüootse mRNA vahel. (1p)
The mRNAs of many bacteria and bacteriophages are polygenic or polycistronic. A polycistronic
mRNA is transcribed by the several structural genes of an operon. It contains several sites for
initiating and terminating polypeptide synthesis. On the other hand all known eukaryotes have only
one site for initiation of protein synthesis. Thus eukaryote mRNAs are monocistronic.
In most bacterial mRNAs translation begins while the mRNA is still being transcribed on DNA. In
eukaryotes the mRNA transcribed on the chromosomes passes through the nuclear pores into the
cytoplasm. Here it forms complexes with ribosomes, which synthesize proteins. Thus translation
usually begins only after transcription is completed.
6. Kataboliitne aktivaator (CAP-valk) seondub: (1p)
c. DNA-le ÕIGE
7. Võrrelge taime- ja loomarakku. 5 erinevust, 5 sarnasust.
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