Question

1. How do ribonucleoside triphosphates differ in structure from deoxyribonucleoside triphosphates?

2. Where do RNA polymerases derive the energy needed for transcription?

3. What are the primary differences between Rho-dependent and Rho-independent termination?

Answer 1

1. Deoxynucleotide triphosphates (dNTPs) are the nucleoside triphosphates that contains deoxyribose. They are the building blocks of DNA that loose two of the phosphate groups when it is incorporated into DNA during the process of replication. dNTPs are used as a substrate in DNA synthesis, while NTPs are used in RNA synthesis. DNA consists of four different nitrogenous bases: They include adenine, guanine, cytosine, and thymine. RNA contains adenine, guanine, and cytosine, but thymine is replaced with uracil.

Ribonucleotide triphosphates are the nucleoside triphosphates that contains ribose. It is the building blocks of DNA and RNA, which are chains of nucleotides made through the processes of DNA replication and transcription. RNA is single-stranded and is made of ribonucleotides that are linked by phosphodiester bonds. A ribonucleotide in the RNA chain contains ribose (the pentose sugar), one of the four nitrogenous bases (A, U, G, and C), and a phosphate group.

2. The transcription is the first step in decoding a cell's genetic information. During transcription, enzymes called RNA polymerases build RNA molecules that are complementary to a portion of one strand of the DNA double helix. The energy for the reaction is derived from splitting the high-energy triphosphate into the monophosphate and releasing the inorganic diphosphates.

3.  Rho-dependent and Rho-independent are the two major termination strategies found in bacteria.
In Rho-dependent termination, the Rh factor binds to RNA or less weakly to DNA that causes polymerase to release, and mRNA is formed.
Rho-independent termination: It occurs via a molecule called palindromes that can form a hairpin loop, and the release of mRNA and polymerase occurs.