What Makes Deoxyribose Essential to DNA and Genetics?
Deoxyribose is a sugar, but not the kind we think about when we want to sweeten our coffee. A monosaccharide is deoxyribose. Monosaccharides serve as the foundation for more complex sugars. The words 'mono' and 'saccharide' mean 'one' and 'sugar,' respectively.
2 Deoxyribose - Deoxyribose Sugar Formula
Deoxyribose is a part of DNA and is often referred to as 2-deoxyribose. A sugar is any molecule that ends in the letter 'ose.' C5H10O4 is the chemical formula for deoxyribose. The letters reflect the names of elements from the periodic table, and the numbers (presented in subscript) tell us how much of each of these elements make up a specific covalent bond. Deoxyribose is made up of 5 carbon atoms, 10 hydrogen atoms, and 4 oxygen atoms, according to the deoxyribose formula. Atoms are the essential chemical elements of life and can be found everywhere.
Monosaccharides, or basic sugars, are ribose and deoxyribose. They are aldopentoses that are phosphorylated to form deoxyribonucleotide and ribonucleotide, respectively. They play a crucial role in the creation of an organism's blueprint, which is passed down over generations.
Nucleotides are the building blocks of nucleic acids, and they aid in the transmission of genetic material. Ribose, which has five carbon atoms, is the pentose sugar for RNA. Deoxyribose is the pentose sugar for DNA.
Emil Fischer discovered ribose in the year 1891. Phoebus Levene discovered deoxyribose in 1929. Below are some structural IUPAC names, molar mass, chemical formula, and other variations between deoxyribose and ribose.
Deoxyribose Sugar Structure
The monosaccharide deoxyribose, or more specifically 2-deoxyribose, has the idealized formula H(C=O)(CH2)(CHOH)3H. Its name denotes that it is a deoxy sugar, meaning that it is created by removing an oxygen atom from the sugar ribose. Deoxyribose is most well-known for its use in DNA.
Ribose and Deoxyribose
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Following are the major difference between deoxyribose and ribose -
Difference between Deoxyribose and Ribose
What is Deoxyribose?
Deoxyribose is an aldopentose sugar with an attached aldehyde group. This aids in the differentiation of ribonucleic and deoxyribonucleic acid by enzymes found in the living body.
Deoxyribose products play an essential role in biology. In all life forms, DNA is the primary source of genetic material. Adenine, thiamine, guanine, and cytosine are among the DNA nucleotides.
What is Ribose?
Ribose is a pentose sugar with an openly attached aldehyde group at the end of the chain. Ribonucleoside is made up of ribose sugar and a nitrogenous base. A ribonucleotide is formed when this ribonucleoside is bound to a phosphate group.
It's a monosaccharide with one oxygen atom attached to each carbon atom. The ribose sugar can be present in living organisms' RNA. RNA is in charge of encoding and decoding genetic material.
Deoxyribose Structure
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(Image will be Updated soon)
Deoxyribose may exist as a five- or six-membered ring or as a linear molecule on its own. Since it is a five-carbon molecule with a carbonyl group at the end, deoxyribose is referred to as an aldopentose. It appears as deoxyribofuranose, or a five-membered ring, in the image above.
Deoxyribose can act as the backbone of DNA by substituting a phosphate group and a nucleic acid base on this ring, as shown in the diagram below.
Deoxyribose Function
Deoxyribose is a five-membered ring found in DNA. Deoxyribose has lost an oxygen molecule from one of the carbons in the ring, as seen in the diagram. Although this may seem to be a minor improvement, it has a significant impact on DNA's resistance to hydrolysis. With the extra oxygen, RNA can interact with water molecules more effectively. The phosphodiester bonds that connect ribose molecules can be hydrolyzed as a result of this. The phosphodiester bonds that connect deoxyribose molecules naturally interact with waterless and break down less through hydrolysis. This allows DNA molecules to be passed down through generations with only small modifications.
To distinguish between the carbons in deoxyribose, the carbons are numbered with primes. The carbon that will be bound to the nitrogenous (nucleic acid) base is the 1' carbon (also known as "the one prime carbon"). The 5' carbon will be on the ring's opposite side and will not be part of the ring's structure. The phosphate group is linked to the 5' carbon. As seen in the diagram, this phosphate group will then bind to the 3' carbon of the nucleotide above it. The covalently bonded backbone of DNA is formed as a result of this. Though not seen, DNA is made up of two strands that complement each other and have deoxyribose backbones. The backbones are held together by hydrogen bonds formed by pyrimidines and purines interacting with one another. Enzymes sever these hydrogen bonds during replication to create new DNA strands that complement each side of the parent strand. Until being deoxygenated into deoxyribose bases, new ribose molecules are bound to nitrogenous bases and phosphate classes. The nucleotides can then be attached to the growing base string, forming an independent DNA molecule.
Importance of Deoxyribose
Deoxyribose forms the very backbone of DNA. It is a pentose sugar and a key building block of DNA. Students need to know about DNA before they read this chapter on the importance of Deoxyribose. DNA is vital as it contains the instructions that an organism needs to develop, survive and reproduce. All those students who wish to pursue Biology later on in life need to know about it. Getting the fundamentals right will assist them in having a grasp over the other related concepts later on.
How to Prepare for a Test on Deoxyribose
A test on Deoxyribose can be prepared for when the students learn about it properly. Once they have understood what it is and why it is important, they can refer to Deoxyribose on Vedantu to understand it better. This page has comprehensive information on the same which the students need to be aware of. They can read from here and then go for the tests.
FAQs on Deoxyribose: Definition, Structure & Role in DNA
1. What is deoxyribose and what is its primary role in living organisms?
Deoxyribose is a modified pentose (five-carbon) sugar that serves as a fundamental structural component of deoxyribonucleic acid (DNA). Its primary role is to form the sugar-phosphate backbone of the DNA molecule. Along with a phosphate group and a nitrogenous base, it makes up a deoxyribonucleotide, the monomer unit of DNA, which carries the genetic instructions for the development, functioning, growth, and reproduction of all known organisms.
2. What are the key differences between the structure of deoxyribose and ribose?
The primary structural difference between deoxyribose and ribose lies in the chemical group attached to the second (2') carbon atom of the sugar ring. Here are the key distinctions:
At the 2' Carbon: Deoxyribose has only a hydrogen atom (–H) at the 2' carbon position, whereas ribose has a hydroxyl group (–OH).
Chemical Formula: Due to the missing oxygen atom, the chemical formula for deoxyribose is C₅H₁₀O₄, while for ribose it is C₅H₁₀O₅.
Nucleic Acid Component: Deoxyribose is the sugar component found in DNA (Deoxyribonucleic Acid), while ribose is found in RNA (Ribonucleic Acid).
Stability: The absence of the reactive hydroxyl group makes deoxyribose, and therefore DNA, more chemically stable than ribose and RNA.
3. How is the backbone of a DNA strand formed with deoxyribose?
The backbone of a DNA strand is a repeating chain of sugar and phosphate units. Deoxyribose molecules are linked together by phosphodiester bonds. Specifically, the phosphate group attached to the 5' carbon of one deoxyribose sugar forms a covalent bond with the hydroxyl (–OH) group on the 3' carbon of the adjacent deoxyribose sugar. This creates a strong and continuous sugar-phosphate backbone that gives the DNA molecule its structural integrity, with the nitrogenous bases attached to the 1' carbon of each sugar, pointing inwards.
4. What are the three components that make up a deoxyribonucleotide?
A deoxyribonucleotide, the monomer unit of DNA, consists of three distinct chemical components:
A five-carbon sugar, which is 2-deoxyribose.
A phosphate group, which is attached to the 5' carbon of the deoxyribose sugar.
One of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), or thymine (T), which is attached to the 1' carbon of the sugar.
5. Why is the more stable deoxyribose used for storing genetic information in DNA, while the less stable ribose is used in RNA?
The choice of sugar is directly related to the function of the nucleic acid. DNA's primary role is the long-term, stable storage of an organism's genetic blueprint. The absence of the reactive 2'-hydroxyl group in deoxyribose makes the DNA molecule much less susceptible to spontaneous hydrolysis (breakdown), ensuring the integrity of the genetic code over long periods. In contrast, RNA has more transient roles, such as acting as a messenger (mRNA) or in protein synthesis (tRNA, rRNA). Its lower stability, due to the reactive 2'-hydroxyl group in ribose, is suitable for these short-term functions, allowing it to be synthesized, used, and degraded as needed by the cell.
6. How does the absence of one oxygen atom in deoxyribose specifically impact the stability of a DNA molecule?
The absence of the oxygen atom at the 2' carbon position is critical for DNA's stability. The 2'-hydroxyl (–OH) group present in ribose (in RNA) is chemically reactive. It can act as a nucleophile in an intramolecular reaction, attacking the adjacent phosphodiester bond. This can lead to the cleavage of the RNA backbone, especially under alkaline conditions. By having only a hydrogen atom at the 2' position, deoxyribose lacks this reactive group. This structural difference prevents self-cleavage and makes the DNA polymer significantly more robust and suitable for its role as a permanent genetic archive.
7. Is deoxyribose classified as a reducing sugar? Explain why.
Yes, deoxyribose is classified as a reducing sugar. This is because, in its open-chain (linear) form, it possesses a free aldehyde group (–CHO) at one end. This aldehyde group can be oxidised (e.g., in a Benedict's test), and in the process, it reduces the other reactant. Although deoxyribose primarily exists in a cyclic (furanose) ring structure within DNA, it is in equilibrium with its open-chain form, which allows it to exhibit the properties of a reducing sugar.
