1. Nucleic Acids
Section 3.5

2. Learning Objectives Describe the components of a nucleotide
Identify the monomer of nucleic acids
Give examples of nucleic acids and types of nucleotides

3. Nucleic Acids
Nucleic acid = macromolecules that transmit hereditary information & decide what proteins a cell makes
Ultimately control the life of a cell
Responsible for gene expression
Monomers are nucleotides
Two types of nucleic acid
DNA – contains instructions for making everything in the cell
RNA – made from DNA template; involved in making proteins for the cell

4. Nucleotides Each nucleotide is made of one: Sugar Phosphate group
Nitrogenous base (5 types: A, T, C, G, & U)
Nitrogenous base (A)
Phosphate group
Sugar
Copyright © 2003 Pearson Education, Inc. publishing Benjamin Cummings

5. DNA & RNA Have Different Sugars
Sugar for DNA is deoxyribose
Sugar for RNA is ribose

6. 5 Types of Nitrogenous Bases
Adenine, Thymine, Guanine, Cytosine, & Uracil
DNA has A, T, G, & C
RNA has A, U, G, & C
Nitrogenous bases are either purines or pyrimidines
Purine = has a double-ring structure (A & G)
Pyrimidine = has a single-ring structure (C, T, & U)

7. Structure of Nucleic Acid
Sugars & phosphates form covalent bonds to make the backbone of the chain
In DNA hydrogen bonds form between nitrogenous bases on opposite strands
Copyright © 2001 Pearson Education, Inc. publishing Benjamin Cummings

8. Deoxyribonucleic acid (DNA)
Made of two polynucleotides twisted around each other in a double helix
The sequence of the four types of nitrogenous bases in DNA carries genetic information
Adenine (A), Thymine (T), Guanine (G), & Cytosine (C)

9. Genes = sections of a DNA molecule that code for the amino acid sequences of proteins
Information in DNA is transcribed into RNA, a single-stranded nucleic acid
RNA is then translated into the primary structure of proteins

10. Ribonucleic Acid (RNA)
A single strand of nucleic acid
Nitrogenous bases are Adenine (A), Uracil (U), Cytosine (C), and Guanine (G)
The sugar in the nucleotides is ribose
Involved in making proteins for the cell

11. Other Uses of Nucleotides
Nucleotides are also used in ATP
A high energy molecule used for work in the cell
Has 3 phosphate groups instead of one
A phosphate group is removed & transferred to the thing that needs to receive energy