Table of Contents
Why is the DNA strand twisted?
The twisting aspect of DNA is a result of interactions between the molecules that make up DNA and water. In order to further prevent the nitrogenous bases from coming into contact with cell fluid, the molecule twists to reduce space between the nitrogenous bases and the phosphate and sugar strands.
Is twisted ladder DNA or RNA?
Concept 19: The DNA molecule is shaped like a twisted ladder. Deoxyribose and phosphate molecules form the uprights and nucleotide pair form the rungs of the DNA ladder.
Why is DNA double stranded and RNA is not?
DNA was chemically more stable than RNA so it was possible to maintain greater length of DNA in comparison to RNA. RNA has hydroxyl group (OH) present on the 2′ carbon. This hydroxyl group invites hydrolysis reaction and so it was not possible to maintain long length RNA molecule.
Why is RNA not single-stranded?
RNA is transcribed from DNA, and in general only transcribed from one strand of the DNA that is set up with initiation site and promoter. Therefore the complimentary strand is never made, and in the absence of complimentary sequences within the single strand, it will be single-stranded.
Is RNA twisted?
Double stranded helical DNA and RNA are flexible molecules that can undergo global conformational fluctuations. Their bending, twisting and stretching deformabilities are of similar magnitude.
Is RNA only single-stranded?
Ribonucleic acid (RNA) is a molecule similar to DNA. Unlike DNA, RNA is single-stranded. An RNA strand has a backbone made of alternating sugar (ribose) and phosphate groups.
Is DNA double stranded and RNA is single-stranded?
In total, RNA contains three hydroxyl groups, while DNA contains only two. In RNA, uracil replaces thymine, not guanine. DNA is generally double-stranded and RNA is generally single-stranded (though both can exist in either form).
Why does DNA twist when it enters a cell?
In order to further prevent the nitrogenous bases from coming into contact with cell fluid, the molecule twists to reduce space between the nitrogenous bases and the phosphate and sugar strands. The fact that the two DNA strands that form the double helix are anti-parallel helps to twist the molecule as well.
Why is DNA double stranded and not single stranded?
Why is DNA double stranded (and not single stranded like RNA)? Firstly, the ‘information’ part of DNA is the nitrogenous base, as opposed to the pentose sugar or the phosphate residues.
Why is DNA a double helix and RNA a single helix?
Very good question; DNA is double helix and RNA is single helix because of their functions inside the cell. DNA is meant to store genetic information for the tenure of the cell’s life and also preserve it for the next generation of cells when it divides.
How is DNA arranged in a DNA molecule?
DNA is arranged such that the phosphate and sugar backbone are on the outside and in contact with fluid, while the nitrogenous bases are in the inner portion of the molecule.