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This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Your purchase has been completed. Your documents are now available to view. Open Access Published by De Gruyter June 3, From the journal Heterocyclic Communications.

Download article PDF. Cite this Share this. Abstract The modification of the ribofuranose in nucleic acids is a widespread method of manipulating the activity of nucleic acids. Keywords: deoxyribose ; nucleic acids ; nucleic acid modification ; pseudorotation ; ribose ; sugar conformation.

Introduction Nucleic acids contain the genetic information for life. Figure 1. Figure 2. Table 1. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Acknowledgements M. Received: Accepted: There are three kinds of substitution mutations:.

Silent mutations do not affect the sequence of amino acids during translation. Nonsense mutations result in a stop codon where an amino acid should be, causing translation to stop prematurely.

Missense mutations change the amino acid specified by a codon. An insertion occurs when one or more bases are added to a DNA sequence. A deletion occurs when one or more bases are removed from a DNA sequence.

Because the genetic code is read in codons three bases at a time , inserting or deleting bases may change the "reading frame" of the sequence.

These types of mutations are called frameshift mutations. This may, in turn, alter which amino acids are added to polypeptide. In this example, the original reading frame of a gene encodes an mRNA with codons that specify the amino acid sequence: methionine Met , isoleucine Ile , argenine Arg , and asparagine Asn.

A deletion of the 4th nucleotide T shifts the reading frame at the point of the deletion. This produces a new reading frame in the DNA template after the 3rd nucleotide. The mRNA of the new frame bears different codons past the point of the mutation the first methionine-specifying codon remains unchanged.

These codons specify the amino acid sequence: methionine Met , tyrosine Tyr , and glycine Gly. As this example illustrates, a frameshift mutation changes how nucleotides are interpreted as codons beyond the point of the mutation, and this, in turn, may change the amino acid sequence.

Common mistakes and misconceptions. Amino acids are not made during protein synthesis. Some students think that the purpose of protein synthesis is to create amino acids. However, amino acids are not being made during translation, they are being used as building blocks to make proteins.

Mutations do not always have drastic or negative effects. Often people hear the term "mutation" in the media and understand it to mean that a person will have a disease or disfigurement.

Mutations are the source of genetic variety, so although some mutations are harmful, most are unnoticeable, and many are even good! Insertions and deletions that are multiples of three nucleotides will not cause frameshift mutations.

Rather, one or more amino acids will just be added to or deleted from the protein. Insertions and deletions that are not multiples of three nucleotides, however, can dramatically alter the amino acid sequence of the protein.

Want to join the conversation? Log in. Sort by: Top Voted. Posted 4 years ago. I really love Khan academy and use it often for school. I struggle to cite khan academy in APA format because there is often no date or author included. Can you tell me where to find this? Downvote Button navigates to signup page.

Flag Button navigates to signup page. Show preview Show formatting options Post answer. Posted 6 years ago. What does affect the m What does affect the mutation in DNA? What is the result of a change in the amino acids?

not sure the answer for your first question but for 2 a change in amino acids results in a different polypeptide which leads to a different protein being formed.

Sometimes it's not that big of a deal but if you look up tay sachs it can also be devastating if the protein is super important. Jarl Riskjell Gjerde. Posted 5 years ago. Are they just floating around in the cytoplasm? Do they enter the nucleus when it's time for transcription?

Is the tRNA floating around in the cytoplasm, waiting for mRNAs that it can latch amino acids onto? There is a massive amount of proteins. How can this be with the seemingly limited combination of amino acids that are created during the synthesis? Thank you in advance. Nisbeth Denelia.

Why is protein synthesis a two-part process. The two parts consist of transcription and translation. Transcription is the step where the genetic information from DNA is copied onto mRNA and sent out of the nucleus.

Translation is when the the mRNA ticks to a ribosome and tRNA joins mRNA to form an amino acid chain and eventually a polypeptide. Direct link to raj. If amino acids are not made during protein synthesis then how and where are they made?

Amino acid synthesis is the set of biochemical processes by which the amino acids are produced. Comment Button navigates to signup page. Posted 3 years ago. why do changes in DNA lead to mutations but changes in the RNA code do not lead to mutations?

In addition to maintaining the GenBank nucleic acid sequence database, the National Center for Biotechnology Information NCBI provides analysis and retrieval resources for the data in GenBank and other biological data made available through the NCBI web site.

Deoxyribonucleic acid DNA is a nucleic acid containing the genetic instructions used in the development and functioning of all known living organisms.

The chemical DNA was discovered in , but its role in genetic inheritance was not demonstrated until The DNA segments that carry this genetic information are called genes.

Other DNA sequences have structural purposes, or are involved in regulating the use of this genetic information. Along with RNA and proteins, DNA is one of the three major macromolecules that are essential for all known forms of life. DNA consists of two long polymers of monomer units called nucleotides, with backbones made of sugars and phosphate groups joined by ester bonds.

These two strands are oriented in opposite directions to each other and are, therefore, antiparallel. Attached to each sugar is one of four types of molecules called nucleobases informally, bases.

It is the sequence of these four nucleobases along the backbone that encodes genetic information. This information specifies the sequence of the amino acids within proteins according to the genetic code.

The code is read by copying stretches of DNA into the related nucleic acid RNA in a process called transcription. Within cells, DNA is organized into long sequences called chromosomes.

During cell division these chromosomes are duplicated in the process of DNA replication, providing each cell its own complete set of chromosomes.

Eukaryotic organisms animals, plants, fungi, and protists store most of their DNA inside the cell nucleus and some of their DNA in organelles, such as mitochondria or chloroplasts.

In contrast, prokaryotes bacteria and archaea store their DNA only in the cytoplasm. Within the chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.

Ribonucleic acid RNA functions in converting genetic information from genes into the amino acid sequences of proteins. The three universal types of RNA include transfer RNA tRNA , messenger RNA mRNA , and ribosomal RNA rRNA.

Messenger RNA acts to carry genetic sequence information between DNA and ribosomes, directing protein synthesis and carries instructions from DNA in the nucleus to ribosome. Ribosomal RNA reads the DNA sequence, and catalyzes peptide bond formation. Transfer RNA serves as the carrier molecule for amino acids to be used in protein synthesis, and is responsible for decoding the mRNA.

In addition, many other classes of RNA are now known. Artificial nucleic acid analogues have been designed and synthesized. Each of these is distinguished from naturally occurring DNA or RNA by changes to the backbone of the molecules.

Contents move to sidebar hide. Article Talk. Read Edit View history. Tools Tools. What links here Related changes Upload file Special pages Permanent link Page information Cite this page Get shortened URL Download QR code Wikidata item.

Download as PDF Printable version. In other projects. Wikimedia Commons. Class of large biomolecules essential to all known life. Main article: Nucleic acid sequence. Further information: Genetics. Main article: DNA. Main article: RNA.

Main article: Nucleic acid analogue. Retrieved 1 January What is DNA. Linda Clarks. Retrieved 6 August Human Genetics. doi : PMID S2CID Principles of Biochemistry.

Susan Winslow. ISBN February Bibcode : Natur. Bibcode : Sci Annual Review of Biochemistry. Brock biology of microorganisms. The Polymerase Chain Reaction Nobel Lecture.

May National Institutes of Health. Nucleic Acids Research. PMC San Francisco: W. Annual Review of Biophysics and Biomolecular Structure. Molecular biology of the cell.

New York: Garland Science. Palou-Mir J, Barceló-Oliver M, Sigel RK Some types of non-coding RNAs RNAs that do not encode proteins help regulate the expression of other genes. Such RNAs may be called regulatory RNAs.

For example, microRNAs miRNAs and small interfering RNAs siRNAs are small regulatory RNA molecules about 22 nucleotides long. They bind to specific mRNA molecules with partly or fully complementary sequences and reduce their stability or interfere with their translation, providing a way for the cell to decrease or fine-tune levels of these mRNAs.

These are just some examples out of many types of noncoding and regulatory RNAs. Scientists are still discovering new varieties of noncoding RNA.

Summary: Features of DNA and RNA. DNA RNA Function Repository of genetic information Involved in protein synthesis and gene regulation; carrier of genetic information in some viruses Sugar Deoxyribose Ribose Structure Double helix Usually single-stranded Bases C, T, A, G C, U, A, G.

Table modified from OpenStax Biology. Explore outside of Khan Academy. Do you want to learn more about nucleotide base-pairing? Check out this scrollable interactive from LabXchange.

Want to join the conversation? Log in. Sort by: Top Voted. kind of blue. Posted 8 years ago. How do mRNA and tRNA communicate with eachother during the formation of the proteins?

Downvote Button navigates to signup page. Flag Button navigates to signup page. Show preview Show formatting options Post answer. Evan Patev. mRNA is like a recipe from a cookbook; a list of ingredients to make a protein.

mRNA is a chain of nucleotides A, U, C, and G, not T since this is RNA. A group of three nucleotides is called a codon. A codon matches with three nucleotides, called an anticodon, on a single tRNA molecule while in a ribosome.

The tRNA carries an amino acid, our ingredient to make the protein. So mRNA is the recipe, tRNA matches to the recipe bringing an ingredient, and the line of ingredients become a protein.

Posted 7 years ago. If A-T bonds have 2 hydrogen bonds and G-C bonds have And if this is true, are these parts AT only parts more prone to mutations? The first part is true, T-A bonds are less stable and more likely to come apart. The A-T bond strands also signal where DNA needs to separate for commonly transcribed genes, such as the TATA Box commonly found just before the beginning of gene sequences.

I'm not sure if they are more prone to mutations though. DNA is common to all organisms, all organisms use the same 4 nitrogenous bases, A T, C G is that right? Matt B. Entirely true. Just keep in mind that, even though all life forms have DNA, not everything that has DNA is alive: viruses can have DNA but are not living.

Are all the 46 chromosomes present in a single cell? shreya punniamoorthy. Yes, all 46 chromosomes are found in each and every cell i. e in every cell there are 46 chromosomes 23 from each parents. Alex Auvenshine.

Are the functions of nucleic acids guided only by molecular forces and just appear to have intention or are there other forces at work that I'm not aware of? How do these macromolecules "know" what to do? Jon Hill.

A creationist would say that this is part of the intelligent design. An evolutionist would say it's all down to chance. Two spanners to consider - 1 one molecule of hormone, once recognised by the cell, leads to prduction of thousands of times more molecules, and types of molecules, than a mere chemical would suggest, and such secretions can be brought about by tiny changes in brain activity.

It is a molecularly inert form for the passing on of genes without having a massive effect upon the rest of the body - and so the active form is the sticky stuff of RNA and these determine how the proteins are folded together.

Why do some nitrogenous bases have two fused carbon rings while other have one? Would it be possible for there to be nitrogenous bases with more than two fused carbon rings? Could there ever be an instance where there are more than just five kinds of nitrogenous bases Adenine, Thymine, Guanine, Cytocine and Uracil?

If it could be possible how would DNA and RNA have to rearrange themselves? Would it be possible for DNA and RNA to use other sugars aside from Deoxyribose and Ribose? If so, like what? If not, why? Comment Button navigates to signup page. Ume Abiha.

Posted 8 months ago. how are DNA and RNA different and alike to each other? As stated in the summary at the end of the article, DNA and RNA have different functions.

While DNA stores genetic information, RNA is involved in protein synthesis and gene regulation, as well as storing genetic information in some viruses. DNA and RNA also have different structures; DNA's phosphate-sugar backbone contains deoxyribose, while RNA's contains ribose.

While DNA is double-stranded and has the nitrogenous bases adenine, thymine, cytosine, and guanine, RNA is usually single-stranded and contains uracil instead of thymine. As for the similarities between DNA and RNA, they are both important biological polymers and contain four bases and a phosphate-sugar backbone.

Prakriti Marwah. When transcription takes place and the DNA is broken into two, and then mRNA is formed with one of the DNA strands or for BOTH the DNA strands?

Within a gene usually only one strand is transcribed, but there are many examples where transcription happens from the both strands. This is especially common in viruses. Also, the strand that is transcribed for one gene may not be the same as the strand being transcribed for a neighboring gene. Finally, the whole DNA double helix is not separated - just a small bubble is opened around each RNA polymerase as it works its way along the DNA.

Leilani Carrillo. Posted 10 months ago. How does tRNA form double-stranded regions if it only consists of 1 strand?

Posted 5 months ago. Direct link to abdullah. It the second strand is the mRNA itself. Posted 2 years ago. WHy has RNA stuck around for so long? Posted a year ago. The answer to that is that RNA is a very versatile and useful molecule.

RNA is a great molecule for living things because it can be used to translate DNA into a form that can make proteins in the ribosomes and also bring the amino acids to the ribosome to be assembled into the polypeptide chain. It can do this and regulate itself and DNA during the development of embryos and help with the replication of DNA by acting as a primer for polymerase.

Plus functions that scientists are only now discovering. You would be hard-pressed to find another molecule that can do all that, and for that reason, RNA has not been replaced.

Involved in protein synthesis and gene regulation; carrier of genetic information in some viruses.