Introduction:
The association of nitrogenous bases and pentose sugars provides the compound known as nucleoside which is component of nucleotides (monomeric units of nucleic acids). Based on type of nitrogenous base and types of sugar it is liked to, different kinds of nucleotides are formed each containing its own characteristic and structure.
Definition of nucleosides:
Nucleosides are organic compounds having pentose sugars and nitrogenous base linked together by N-β-gylcosidic bond. Sugar can either be ribose sugar or deoxyribose sugar while nitrogenous bases are: Guanine, Adenine, Cytosine, Thymine or Uracil etc.
Components of nucleoside:
Components of nucleosides are essentially nitrogenous bases and pentose sugars.
Nitrogenous bases and their structures:
Nitrogenous bases present in nucleosides are either purines or pyrimidines and are given below. Purine bases contains purine ring (double ring system) while pyrimidine base contain pyrimidine ring (single ring structure).
The purine bases are:
Adenine denoted by A and has the structure:
Guanine denoted by G and has the following structure:
The pyrimidine bases are cytosine, thymine and uracil
Cytosine denoted by C and has the following structure
Thymine denoted by T and has the structure below
Uracil, denoted by U and has the structure below:
Additionally to purine bases A and G other unusual purine bases do exist and they comprise: hypoxathine, 1 methylguanine, 1 methylhypoxanthine etc. Unusual pyrimidine bases also exist and they are derived from cytosine, thymine and uracil and they comprise: 5-methylcytosine, Thiouracil etc.
Pentose sugars and their structures:
The pentose (5 carbon) sugars of nucleoides are basically ribose or (ribofuranose) 2' deoxyribose (2' deoxyribofuranose). The 2' deoxyribose sugar is found in deoxyribonucleic acid (DNA) while the ribose sugar is found in ribonucleic acid (RNA).
Linkages between pentose sugars and nitrogenous Bases in nucleosides:
In nucleosides, nitrogenous bases are joined to pentose sugar through the hemiacetal hydroxyl group on the C-1 (first carbon atom of the sugar). Generally, the purines are attached to the sugar through the N-9 nitrogen atom while pyrimidine is attached through the N-1 nitrogen atom.
Common purine and pyrimidine nucleosides and their Structures:
Purine Nucleosides:
Pyrimidine Nucleosides:
Nomenclature of nucleosides:
Nucleosides are named based on kind of ribose sugar attached to nitrogenous base and whether base present in nucleoside is the purine or pyrimidine.
All purine nucleoside names end with the suffix (-osine) added to name of purine base irrespective of whether it has ribose or deoxyribose sugar. Examples comprise: Adenosine, guanosine, deoxynadenosine and deoxyguanosine. If purine nucleoside has the deoxyribose sugar then prefix (-deoxy) is added to name of its ribonucleoide counterpart example deoxyadenosine and deoxyguanosine are deoxyribonucleosides of adenosine and guanosine respectively.
For naming of pyrimidine ribonucleoside the suffix (-idine) is added to name of base in nucleoside. Example ribonucleoside of uracil is named uridine, (-acil) of uracil is replaced by (-idine). Cytosine ribonucleoside is named Cytidine while that of Thymine is Thymidine. On other hand pyrimidine deoxyribonucleoside are named by adding the prefix 2' deoxy to name of its pyrimidine ribonucleosides counterpart like 2' deoxythymididine, 2' deoxycytidine, 2'deoxyadenosine, 2'deoxyguanosine and 2'deoxyuridrine.
Tutorsglobe: A way to secure high grade in your curriculum (Online Tutoring)
Expand your confidence, grow study skills and improve your grades.
Since 2009, Tutorsglobe has proactively helped millions of students to get better grades in school, college or university and score well in competitive tests with live, one-on-one online tutoring.
Using an advanced developed tutoring system providing little or no wait time, the students are connected on-demand with a tutor at www.tutorsglobe.com. Students work one-on-one, in real-time with a tutor, communicating and studying using a virtual whiteboard technology. Scientific and mathematical notation, symbols, geometric figures, graphing and freehand drawing can be rendered quickly and easily in the advanced whiteboard.
Free to know our price and packages for online biology tutoring. Chat with us or submit request at [email protected]
tutorsglobe.com sales and consumer law assignment help-homework help by online humanities tutors
tutorsglobe.com theories of coordination compounds assignment help-homework help by online coordination compounds tutors
Even though ratios present a quick and useful method of analysing the position and performance of a business, they are not without their limitations and problems.
tutorsglobe.com glucose tolerance test assignment help-homework help by online diabetes mellitus tutors
www.tutorsglobe.com offers Object Oriented Architectures homework help, assignment help, case study, writing homework help, online tutoring assistance by computer science tutors.
theory and lecture notes on the concept of fundamental electric circuit laws and ohms law all along with the key concepts of ohm’s law, kirchhoffs circuit laws, kirchhoffs current law and kirchhoffs voltage law. tutorsglobe offers homework help, assignment help and tutor’s assistance on the concept of fundamental electric circuit laws and ohms law.
www.tutorsglobe.com offers nasa model homework help, assignment help, case study, writing homework help, online tutoring assistance by computer science tutors.
Principles of independent assortment tutorial all along with the key concepts of Mendel's Second Law , Law of Independent Assortment and The Rules of Probability
application and scope of managerial economics including the key concepts of managerial economics, average value, horizontal boundaries, marginal value, vertical boundaries, imperfect market, economic model, market power and stock
An automatic Volume control is used in radio receiver additionally to the manual volume control. It gives stability to the output.
buoyancy-archimedes principle tutorial all along with the key concepts of concepts of buoyancy, archimedes' principle, relative density, application of archimedes' principle, law of floatation
tutorsglobe.com society and culture assignment help-homework help by online humanities tutors
www.tutorsglobe.com offers properties of amines homework help, properties of amines assignment help, online tutoring assistance, organic chemistry solutions by online qualified tutor's help.
theory and lecture notes of markets and equilibrium all along with the key concepts of markets and equilibrium, markets, equilibrium, homework help, assignment help and understanding macroeconomics. tutorsglobe offers homework help, assignment help and tutor’s assistance on markets and equilibrium.
Taxonomy of invertebrates tutorial all along with the key concepts of Classification of Invertebrates, Protozoa, Echinoderms, Annelids, Mollusks, Arthropods, Crustaceans, Arachnids and Insects
1957781
Questions Asked
3689
Tutors
1452145
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!