1. Biology, 9th ed,Sylvia Mader
Chapter 03
Nucleic Acids
Polymers of nucleotides
Very specific cell functions
DNA (deoxyribonucleic acid)
Double-stranded helical spiral (twisted ladder)
Serves as genetic information center
In chromosomes
RNA (ribonucleic acid)
Part single-stranded, part double-stranded
Serves primarily in assembly of proteins
In nucleus and cytoplasm of cell
Organic Chemistry

2. The Nucleotides of Nucleic Acids
Biology, 9th ed,Sylvia Mader
Chapter 03
The Nucleotides of Nucleic Acids
Three components:
A phosphate group,
A pentose sugar (ribose or deoxyribose), and
A nitrogenous base (4 kinds in DNA, 3 kinds in RNA, 3 common to both)
Nucleotide subunits connected end-to-end to make nucleic acid
Sugar of one connected to the phosphate of the next
Sugar-phosphate backbone
Organic Chemistry

3. Nucleic Acids
Nucleic acids are compounds made of long, repeating chains called nucleotides.
Each nucleotide contains:
a sugar molecule
a phosphate molecule, and
a base molecule.

4. DNA and nucleic acids DNA is a nucleic acid .
A DNA molecule is twisted in a double helix arrangement
This model shows a short piece of the flattened DNA ladder.
A DNA molecule is usually twisted and much longer.

5. DNA Each side of the ladder is made of:
5-carbon sugars called deoxyribose
and phosphate groups.

6. DNA
There are four nitrogen bases in two matched pairs.

8. Biology, 9th ed,Sylvia Mader
Chapter 03
Nucleotides
Organic Chemistry

9. a b
Cytosine and thymine are derivatives of the compound pyrimidine, and as a result are referred to as pyrimidine bases.
Adenine and guanine are derivatives of the compound purine , and as a result are referred to as purine bases.

10. Nucleic Acids
Sstructure of a phosphate group, deoxyribose sugar group, and bases adenine, thymine, guanine, and cytosine. * indicates the site where the base bonds to the C1 deoxyribose carbon atom.

14. Biology, 9th
DNA Structure
Chapter 03
Organic Chemistry

15. Comparison of DNA & RNA Feature DNA RNA Sugar Bases Strands Helix
Biology, 9th
Chapter 03
Comparison of DNA & RNA
Feature
DNA
RNA
Sugar
Deoxyribose
Ribose
Bases
Cytosine, guanine; adenine, thymine
Cytosine, guanine;
adenine, uracil
Strands
Double-stranded; Pairing across strands
Mostly single stranded
Helix
Yes No
Function
Heredity; cellular control center
Interprets genetic info; protein synthesis
Where
Chromosomes of cell nucleus
Cell nucleus and cytoplasm
Organic Chemistry

16. Biology, 9th
Chapter 03
Other Nucleic Acids
ATP (adenosine triphosphate) is composed of adenine, ribose, and three phosphates
In cells, one phosphate bond is hydrolyzed – Yields:
The molecule ADP (adenosine diphosphate)
An inorganic phosphate molecule pi
Energy
Other energy sources used to put ADP and pi back together again
Organic Chemistry