Question

There are similarities between DNA synthesis and RNA synthesis in prokaryotes. Compare and contrast the following items. Write in logical organization. List 4 ways to show the different properties of DNA polymerase and RNA polymerase. (4 marks) 1.

Answer 1

SIMILARITIES BETWEEN DNA SYNTHESIS AND RNA SYNTHESIS IN PROKARYOTES.

• DNA Synthesis is the process whereby deoxy nucleic acids (Adenine, Thymine, Cytosine, and Guanine)are linked together to form DNA. NA Synthesis is also known as Transcription. It is the production of RNA molecule from the nucleotides Adenine,Cytosine,Guanine,or Uracil.The nucleotides are joined together by the enzyme RNA Polymerase.
• Structurally DNA and RNA are very similar  with a few differences. They are both made up of monomers called Nucleotides. Nucleotides simply refer to nitrogenous bases, Pentose sugar together with phosphate backbone.

• Both DNA and RNA have four nitrogenous bases each - three of which they share ie, Cytosine, Adenine, and Guanine. And one that differs between the two are; ie, RNA has Uracil while DNA has Thymine.

• DNA is double-stranded, while RNA is single stranded.
• DNA is more structurally stable compared to RNA.
• Both contain a pentose sugar, DNA is a deoxyribose, a characteristic referring to the hydrogen where the hydroxyl group is on the ribose of the RNA molecule.
• Both have a Phosphate backbone to which the bases attach. Because of the Phosphate group this backbone is negatively charged.

DIFFERENT PROPERTIES OF DNA POLYMERASE AND RNA POLYMERASE

1. DNA Polymerase synthesizes a DNA strand and used in DNA Replication, while RNA Polymerase is used during transcription to synthesize the mRNA strand.
2. In contrast with the DNA Polymerase , RNA Polymerases do not necessarily require the so called primer to start the process and they actually have no proofreading systems.
3. RNA Polymerases are capable of initiating a new strand , but DNA Polymerases can not.
4. Subunits contained in RNA Polymerases must unwind the template of DNA and the DNA Polymerases do actually abide the helicase that the double helix may be open just in front of it.
5. DNA Polymerase is a lot faster compared to RNA Polymerase. RNA Polymerase is about 10x slower than DNA Polymerase.