1. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 17 Nucleic Acids and Protein Synthesis 17.2 Primary Structure of Nucleic Acids 1

2. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Nucleic Acids Nucleic acids are polymers of nucleotides (nucleosides with a phosphate group bonded to −OH on C5') have a unique sequence of bases in RNA, which is called its primary structure carry information from one cell to the next 2

3. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Draw the base adenosine-5'-monophosphate (AMP). 3

4. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Draw the base adenosine-5'-monophosphate (AMP). 4

5. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Primary Structure of Nucleic Acids In the primary structure of nucleic acids, nucleotides are joined by a 3'−5' phosphodiester bond the 3'-OH group of the sugar in one nucleotide forms an ester bond to the phosphate group on the 5'-carbon of the sugar of the next nucleotide 5

6. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Example of Phosphodiester Bonds The following nucleotide sequence starting with adenine (free -5'-phosphate end) is 5'–A–C–G–U–3', with nucleotides joined by phosphodiester bonds. 6

7. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Primary Structure of Nucleic Acids In the primary structure of nucleic acids in DNA and RNA chains, each sugar in a sugar−phosphate backbone is attached to a base the bases extend out from the nucleic acid backbone are labeled starting with the free 5' end to the 3' end. In this nucleic acid, the sequence of bases is represented by 5'−A−C−G−U−3'. 7

8. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Primary Structure of Nucleic Acids In the primary structure of RNA, A, C, G, and U are linked by 3−5' -phosphodiester bonds. 8

9. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Fill in the blank: In a nucleic acid the nucleotides are joined by a ___________bond that joins the 3'−OH group of the sugar to the phosphate group on the 5C' on the next nucleotide. 9

10. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Fill in the blank: In a nucleic acid the nucleotides are joined by a phosphodiester bond that joins the 3'−OH group of the sugar to the phosphate group on the 5C' on the next nucleotide. 10

11. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Draw the structure of the dinucleotide A−C in RNA. 11

12. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Draw the structure of the dinucleotide A−C in RNA. 12