why the DNA molecules held toghether by hydrogen bond but RNA are by phosphodister bond
DNA and RNA are both nucleic acids, composed of repeating units called nucleotides. Each nucleotide consists of a sugar molecule (deoxyribose in DNA and ribose in RNA), a phosphate group, and a nitrogenous base.
In DNA, the sugar molecules are connected to each other by phosphodiester bonds. These bonds form between the phosphate group of one nucleotide and the hydroxyl (OH) group of the sugar molecule of the adjacent nucleotide. This linkage creates a sugar-phosphate backbone, which provides stability to the DNA molecule.
On the other hand, hydrogen bonds are responsible for holding the nitrogenous bases in DNA and RNA together. In DNA, there are four different bases: adenine (A), thymine (T), cytosine (C), and guanine (G). The hydrogen bonds form between complementary base pairs: A pairs with T (forming two hydrogen bonds) and C pairs with G (forming three hydrogen bonds). These hydrogen bonds are relatively weak, allowing the two strands of DNA to separate during replication and transcription processes.
In RNA, the basic structure is similar to DNA, but it contains the base uracil (U) instead of thymine (T) and the sugar ribose instead of deoxyribose. Like DNA, RNA molecules are also held together by phosphodiester bonds between the sugar molecules. However, RNA is typically single-stranded, and the hydrogen bonding occurs within the molecule itself, forming secondary structures such as hairpins and loops.
The difference in the type of bonds between DNA and RNA is primarily due to their respective functions. DNA carries genetic information and needs to remain stable, while RNA is involved in various biological processes, including protein synthesis, and requires more flexibility and structural versatility.
DNA molecules are held together by hydrogen bonds between the nucleotide bases. The nucleotide bases in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G). Adenine forms two hydrogen bonds with thymine, while cytosine forms three hydrogen bonds with guanine.
On the other hand, RNA molecules are not primarily held together by hydrogen bonds but rather by phosphodiester bonds. RNA is composed of nucleotides that contain the same four bases as DNA (A, U, C, G) with the exception of thymine being replaced by uracil (U). These nucleotides connect to each other through phosphodiester bonds, which form between the 3' carbon of one nucleotide and the 5' carbon of the next nucleotide. This bond linkage creates a backbone for the RNA molecule.
The difference in the bonding between DNA and RNA is due to their distinct functions in the cell. DNA serves as the genetic material, while RNA is involved in protein synthesis and other cellular processes. The specific bonding arrangements in each molecule contribute to their unique structures and functions.
DNA molecules are held together by hydrogen bonds between complementary base pairs. These base pairs consist of adenine (A) with thymine (T), and guanine (G) with cytosine (C). The hydrogen bonds form between the nitrogenous bases of the two DNA strands and provide stability to the double helix structure.
To understand why DNA is held together by hydrogen bonds, we first need to understand the structure of DNA. DNA is composed of two strands arranged in a double helix shape. Each strand is made up of repeating units called nucleotides. Nucleotides consist of three components: a nitrogenous base, a sugar molecule (deoxyribose), and a phosphate group.
The hydrogen bonds in DNA form between the nitrogenous bases of the two strands. Adenine forms two hydrogen bonds with thymine, while guanine forms three hydrogen bonds with cytosine. These hydrogen bonds are relatively weak compared to the covalent bonds within the DNA molecule, which allow for the separation of the two strands during processes like DNA replication and transcription.
In contrast, RNA molecules are single-stranded and do not form a double helix structure. RNA also consists of nucleotides, but instead of thymine (T), it contains uracil (U). RNA is held together by phosphodiester bonds between adjacent nucleotides in the same strand. Phosphodiester bonds are strong covalent bonds that form between the phosphate group of one nucleotide and the sugar molecule of the next nucleotide.
The reason why RNA is held together by phosphodiester bonds rather than hydrogen bonds is because its single-stranded structure does not require the same level of stability as DNA. Furthermore, the presence of a hydroxyl group (-OH) in the sugar molecule of RNA instead of the deoxyribose sugar in DNA allows for the formation of phosphodiester bonds instead of hydrogen bonds.
In summary, DNA molecules are held together by hydrogen bonds between complementary base pairs, while RNA molecules are held together by phosphodiester bonds between adjacent nucleotides in the same strand. The difference in bonding is due to the structural and functional differences between DNA and RNA.