Biomolecules Test - 88

The m-RNA is mainly used as a template for protein translation. RNA interference (RNAi) is a biological process which involves the obstruction of the phenomena of gene expression, by causing the destruction of specific mRNA molecules. Andrew Fire and Craig C. Mello shared the 2006 Nobel Prize in Physiology or Medicine for their work on RNA interference in the nematode worm Caenorhabditis elegans, which they published in 1998. Two types of small ribonucleic acid (RNA) molecules microRNA (miRNA) and small interfering RNA (siRNA)  are central to RNA interference.

Histone proteins are rich in basic amino acids and form the core around which the DNA is wound giving rise to nucleosome particles. DNA is wound around histones because basic amino acids are positively charged at physiological pH which facilitates winding of acidic or negatively charged DNA. Neutralization of positive charge, on basic amino acids of histone proteins, by chemical processes like reversible acetylation will lead to neutralization of attractive force between nucleosome core and DNA molecule. This will in turn lead to transcriptional activation (histone proteins are acetylated) and after transcription once again the histone proteins will be deacetylated restoring there positive charge, thus facilitating the tight binding between (negatively charged) DNA and (positively charged) histone core. Apart from reversible acetylation, histone proteins also undergo a number of other chemical modifications. Thus, acting as modulators for DNA metabolism.

Toluidine blue is a basic dye with high affinity for acidic tissue components. The nucleic acids are stained blue and polysaccharides purple. It is especially useful today for staining chromosomes in plant or animal tissues, as a replacement for aceto-orcein stain. Toluidine blue staining is the best method for quantitative staining of RNA. It is a specific stain to RNA and not for DNA, chitin, and lignin.

The enzyme that cause chromosomal breaks are DNase. A deoxyribonuclease or DNase, is any enzyme that catalyzes the hydrolytic cleavage of phosphodiester linkages in the DNA backbone, thus degrading DNA. Deoxyribonucleases are one type of nuclease, a generic term for enzymes capable of hydrolising phosphodiester bonds that link nucleotides.

Molecular weight is the mass of a molecule. It is calculated as the sum of the mass of each constituent atom multiplied by the number of atoms of that element in the molecular formula. So, the molecular weight of DNA is the highest while that of tRNA is the least.
So, the correct answer is option C.

• Saccharin is an artificial sweetener with no effective food energy and is about 300 times sweeter than sucrose.
• DNA is less reactive than RNA because the DNA is a double helix structure with no sites available for attachment or reaction.
• RNA mutates faster than DNA because RNA is formed during transcription that increases the chances of mutation during the phase.  
• The processing of hnRNA (heterogenous nuclear RNA) includes the addition of a cap, 5'methyl guanosine, added immediately after transcription begins. This reaction is catalysed by guanylyltransferase.

Tobacco mosaic virus (TMV) is a positive-sense single-stranded RNA virus. TMV is composed of RNA and protein. Tobacco mosaic virus has a rod-like appearance. Its capsid is made of coat protein and one molecule of genomic single strand RNA, 6400 bases long. The coat protein self-assembles into the rod-like helical structure around the RNA which forms a hairpin loop structure.

Proteins are made up of up to 20 different amino acids, so proteins are heteropolymer. 

Reverse transcription was discovered by Temin and Baltimore. It is a process which mainly converts the RNA template to the cDNA by reverse transcriptase.

Proteins are found in all living organisms and are composed of molecules called amino acids. Each amino acid contains four elements they are hydrogen, oxygen, nitrogen and carbon and in certain cases may also contain sulfur.