What is the relationship between the nucleotides, nucleic acids, and DNA? | Socratic
DNA itself is a nucleic acid, that's why it's called Deoxyribonucleic Acid. Nucleotides are a part of DNA. What is the main difference between a nucleotide and a nucleic acid? Views · What is the difference between an adenosine nucleotide found in a nucleic acid and ATP? Views General nucleotide structure. DNA. What are they made of? This article covers the basics. What Are Nucleotides & Nucleic Acids? Nucleotide Structure: Purines & Pyrimidines. Page last updated.
Nicking of circular DNA occurs naturally during DNA replication and can be induced experimentally with a low concentration of deoxyribonuclease a DNA-degrading enzymeso that only a single phosphodiester bond in the molecule is cleaved.
The study of circular DNA molecules lacking free ends first uncovered the complicated geometric shape changes that the double-stranded DNA molecule must undergo when the strands are not free to separate.
In addition, when the two ends of a DNA molecule are fixed, the molecule exhibits a superstructure under certain conditions. This occurs when the base pairing is interrupted and a local region unwinds.
The stress induced by unwinding is relieved by twisting of the double helix on itself, forming supercoils Figure Unwinding and subsequent supercoiling occurs during replication, transcriptionand binding of many proteins to circular DNAs or to long DNA loops whose ends are fixed within eukaryotic chromosomes.
Structural Biochemistry/Nucleic Acid/Difference between DNA and RNA
Supercoiling is recognized and regulated by enzymes called topoisomerases. If one strand is nicked, the strands more Unlike DNAwhich exists primarily in a single, very long three-dimensional structure, the double helix, the various types of RNA exhibit different conformations.
Differences in the sizes and conformations of the various types of RNA permit them to carry out specific functions in a cell. The simplest secondary structures in single-stranded RNAs are formed by pairing of complementary bases. Figure RNA secondary and tertiary structures. In stem-loops, the single-stranded loop dark red between the base-paired more As discussed in detail later, tRNA molecules adopt a well-defined three-dimensional architecture in solution that is crucial in protein synthesis.
Larger rRNA molecules also have locally well defined three-dimensional structures, with more flexible links in between. Secondary and tertiary structures also have been recognized in mRNA, particularly near the ends of molecules.
- What is the relationship between the nucleotides, nucleic acids, and DNA?
- 28.1: Nucleotides and Nucleic Acids
These recently discovered structures are under active study. Clearly, then, RNA molecules are like proteins in that they have structured domains connected by less structured, flexible stretches.
Nucleotides & Nucleic Acids: ATP, RNA & DNA
Some RNA domains also can catalyze RNA splicinga remarkable process in which an internal RNA sequence, an intronis cut and removed and the two resulting chains, the exonsare sealed together.
This process occurs during formation of the majority of functional mRNA molecules in eukaryotic cells, and also occurs in bacteria and archaea. Remarkably, some RNAs carry out self-splicing, with the catalytic activity residing in the intron sequence.
The mechanisms of splicing and self-splicing are discussed in detail in Chapter As noted later in this chapter, rRNA is thought to play a catalytic role in the formation of peptide bonds during protein synthesis.
In later chapters we will encounter other RNAs, often associated with proteins, that participate in other cell functions.
Each nucleotide consists of a heterocyclic base linked via a five-carbon sugar deoxyribose or ribose to a phosphate group see Figure The bases in nucleic acids can interact via hydrogen bonds. Having four different nitrogenous bases: RNA is a polymer with a ribose and phosphate backbone. Four different nitrogenous bases: Structure of ribose in RNA Structure of deoxyribose in DNA Functions[ edit ] DNA is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms.
It is a medium of long-term storage and transmission of genetic information, while RNA is a nucleic acid polymer that plays an important role in the process of translating genetic information from deoxyribonucleic acid DNA into protein products. However, no primer is needed for RNA. In addition, RNA polymerase lacks the ability to detect errors of base pairing, a trait that DNA polymerase is not capable of doing.
DNA is stable in alkaline conditions. It has smaller grooves where the damaging enzyme can attach which makes it harder for the enzyme to attack DNA; RNA, on the other hand, has larger grooves which makes it easier to be attacked by enzymes. RNA, ribose sugar is more reactive because of the presence of hydroxyl group on C 2.