Podcast
Questions and Answers
What is the main structural difference between DNA and RNA?
What is the main structural difference between DNA and RNA?
Which of the following is a nucleoside analogue used in antiviral therapy?
Which of the following is a nucleoside analogue used in antiviral therapy?
What is the structural level of organization for a nucleotide?
What is the structural level of organization for a nucleotide?
What is the importance of nucleoside and nucleotide analogues in medicine?
What is the importance of nucleoside and nucleotide analogues in medicine?
Signup and view all the answers
What is the difference between a nucleoside and a nucleotide?
What is the difference between a nucleoside and a nucleotide?
Signup and view all the answers
What is the orientation of the glycosidic bond in the syn conformation of a nucleotide?
What is the orientation of the glycosidic bond in the syn conformation of a nucleotide?
Signup and view all the answers
Which of the following is a physiologic mediator that is an adenosine nucleotide?
Which of the following is a physiologic mediator that is an adenosine nucleotide?
Signup and view all the answers
What is the structural component of coenzymes NAD and NADP that is derived from a nucleotide?
What is the structural component of coenzymes NAD and NADP that is derived from a nucleotide?
Signup and view all the answers
Which of the following is a structural component of the coenzyme S-adenosylmethionine (SAM), which is involved in methylation reactions?
Which of the following is a structural component of the coenzyme S-adenosylmethionine (SAM), which is involved in methylation reactions?
Signup and view all the answers
What is the orientation of the glycosidic bond in the anti conformation of a nucleotide?
What is the orientation of the glycosidic bond in the anti conformation of a nucleotide?
Signup and view all the answers
Study Notes
Nucleosides
- Composed of a nitrogenous base and a pentose sugar.
- Linked by a glycosidic bond, specifically a β-glycosidic bond (upward directed at C1').
- Designation of bonds: “N” indicates attachment to the nitrogen atom of the base.
Types of Nucleosides
- Ribonucleosides: Contain ribose with a hydroxyl group at C2’.
-
Purines: Form β-glycosidic bond between N9 (base) and C1’ (sugar). Nomenclature ends in -osine. Examples:
- Adenosine (A)
- Guanosine (G)
-
Pyrimidines: Form β-glycosidic bond between N1 (base) and C1’ (sugar). Nomenclature ends in -idine. Examples:
- Cytidine (C)
- Uridine (U)
Functions of Nucleotides
- Serve as chemical energy carriers in cells.
- ATP: Known as the universal energy currency.
- GTP: Contains a purine base.
- CTP: Contains a pyrimidine base.
Nucleotides
- Adenosine monophosphate (AMP): Comprised of adenine, ribose, and one phosphate.
- Phosphate linkage: Found at C3’ and C5’ of sugar, leading to cyclic adenosine monophosphate (cAMP), which acts as a secondary messenger.
Deoxyribonucleotides
-
Names and abbreviations:
- Deoxyadenosine monoPO4 (dAMP)
- Deoxyguanosine monoPO4 (dGMP)
- Deoxycytidine monoPO4 (dCMP)
- Deoxythymidine monoPO4 (dTMP)
- Inosine is formed when hypoxanthine attaches to a ribose ring, produced during purine nucleotide synthesis.
- Hypoxanthine: Not found in DNA, but a degradation product of purine bases.
Nucleobase Analogues
- Compounds that resemble natural nucleobases, important for clinical applications.
- Nomenclature based on phosphate attachment:
- "mono-" for one phosphate
- "di-" for two phosphates
- "tri-" for three phosphates
Purine Analogues
- Hypoxanthine: Contains one oxygen group at C6.
- Xanthine: Contains two oxygen groups at C2 and C6.
- Uric acid: Contains three oxygen groups at C2, C5, and C8.
Summary
- Nucleosides consist of a nitrogenous base and a sugar, with specific nomenclature depending on their structure.
- Nucleotides perform vital functions in energy transfer.
- Deoxyribonucleotides and nucleobase analogues have distinct characteristics essential for biological processes.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge of nucleosides, their composition, and glycosidic bonding in this biochemistry quiz. Learn about ribonucleosides, purines, and pyrimidines.
