Which structural component is found in dna but not in rna?
a. ribose
b. deoxyribose
c. phosphate group
d. nitrogenous base

I believe the correct answer is B. Deoxyribose

The nucleotide of a DNA is slightly different to that of RNA due to an addition of a hydroxyl (OH) on the sugar molecule on the RNA nucleotide located on position 2 of the nucleotide.

The DNA and RNA molecules are almost similar.

They both have a nitrogenous base on position one. The nitrogenous base can be one of the 5 bases Adenine, Cytosine, Guanine or Thymine which can be coded by their alternate Uracil in the right places. They are considered to be the building blocks of the DNA and RNA molecules.

Located on position 5 of the nucleotide of both in RNA and DNA is the phosphate group. It has important functions including forming part of an ATP molecule to provide the body with the required energy. They also activate proteins through a process called phosphorilation for example in the cAMP cycle they activate protein kinases.

On the second carbon position there is a ribose sugar. It has only one oxygen molecule linked to each one of the 5 carbon atoms. On the second carbon position, the oxygen molecule is bound to a hydrogen atom forming a hydroxyl (OH). It is only in the RNA that the ribose sugar exists giving it its name; Riboneucleic acid.

The prefix deoxy- means that lack of oxygen. That is where the name deoxyribonucleic acid (DNA) comes from. On the second carbon position of the nucleotide is where there is lack of the oxygen molecule that usually binds to the carbon and hydrogen molecules leaving a hydrogen only bound to the 2nd carbon position.  This sugar is only found in the DNA molecule. This small lack of an oxygen bound to the hydrogen allows specific enzymes to be able to identify the difference between a DNA molecule and an RNA molecule.

Level: College

Subject: Biology

Topic: Genetics

Difference between the two, DNA and RNA, is that DNA comprises of deoxyribose sugar while RNA comprises of the ribose sugar.

Further Explanation:

DNA and RNA are known to be the most vital molecules in the field of cell biology and is responsible for storing as well as reading the genetic information which basically underpins all life. They are both known to be linear polymers comprising phosphates, sugars, and bases.

DNA or deoxyribonucleic acid and RNA or ribonucleic acid are basically polymers comprises of monomers which are called nucleotides. A molecule of RNA comprises of 5 carbon sugar-phosphate associated with one of the four nucleic acid bases, namely, cytosine, guanine, uracil, and adenine. RNA comprises of a ribose sugar, with the hydroxyl modifications. RNA comprises of only one strand and is also known to be shorter as compared to DNA molecule. As RNA comprises of a ribose sugar, it is known to be more reactive as compared to the molecule of DNA.  

In a molecule of DNA, the sugar is lacking the hydroxyl group at the 2’ position and the thymine base is observed instead of uracil. DNA comprises of two strands and it is arranged in a double-helical structure. DNA is considered to be more stable as compared to the RNA molecule due to which, it is useful for the DNA molecule to carry the responsibility for storing the genetic information safely.

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Answer details:

Grade: Middle school

Subject: Biology

Chapter: Molecular Biology

Keywords:

DNA, RNA, double helix, a ribose sugar, deoxyribose sugar, phosphates, nucleotides, adenine, thymine, cytosine, guanine, and uracil.  

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