Discuss the control of transcription in prokaryotic cells Assignment

Discuss the control of transcription in prokaryotic cells - Assignment Example They possess flagella which accounts for the motility of some prokaryotes. These organisms do not contain intracellular membrane bound organelles such as mitochondria and lysosmes. The size of their ribosomes is 70S which is small as compared to that of eukaryotic cells. The most important and distinguishing feature of prokaryotes is regarding their genetic material. They possess both DNA and RNA but their DNA is single stranded. Their genetic material does not lie in a nucleus rather in a nucleoid which does not have a nuclear membrane and consists of DNA which is in a circular form and is loose. The DNA of the prokaryotes is double stranded. This DNA is also not folded and arranged around histones. The prokaryotes do not contain sterols except for one exception which is Mycoplasma Bacterium which contains them. Prokaryotes are organisms which can survive in extreme conditions as for example at temperatures ranging as high as 80 degrees centigrade. The formation of RNA from DNA is termed as transcription. This process is very essential because it is this RNA which then codes for amino acids and hence proteins. The process of transcription is accomplished by an enzyme known as RNA polymerase. The strand of the DNA that is transcribed is in the 3’ to 5’ direction. Hence the transcript that is formed in the opposite direction that is 5’ to 3’ direction. This is because the RNA polymerase functions in the 3’ to 5’ direction on the DNA creating a complementary strand on RNA in which the Adenine always pairs with Uracil whereas the guanine always pairs with the the cytosine. Prokaryotic cells contain only one type of RNA polymerase. This RNA polymerase only is responsible for the formation of all the different types of RNA in the prokaryotes which includes the mRNA, rRNA and tRNA. RNA polymerase has a distinguishing quality that it can initiate the process of