This document defines nucleic acids and their components. Nucleic acids are made of nucleotides, which contain a nitrogenous base, a 5-carbon sugar called ribose, and a phosphate group. There are two types of nucleic acids: DNA contains the sugar deoxyribose and is found in cells, while RNA contains ribose and helps synthesize proteins. DNA and RNA are made of strands with complementary nucleotide bases that allow them to pair up in structures like the DNA double helix. The "central dogma" of biology describes how DNA is transcribed into RNA and then translated into proteins.

1. Organic Molecule: Nucleic Acids
Prepared by:
MR. KEVIN FRANCIS E. MAGAOAY
Faculty, SHS Biology Department
C h a p t e r 11

2. Learning Objectives:
 Define nucleic acids
 Describe the synthesis of nucleic acids
 Characterize and enumerate the components of
nucleotide
 Differentiate DNA and RNA
 Describe central dogma
 Learn the process of transcription and translation

3. Overview:
 Definition of nucleic acid
 Component of nucleotide
 Classifications of nucleic acids
 Structure of nucleic acids
 Central dogma

4. Nucleic Acid
 The most important macromolecule for the
continuity of life
 Nucleic acids carry the genetic blueprint of a
cell and carry instructions for the functioning of
the cell
 Provide information to make proteins

5. Nucleic Acid
 The monomer of nucleic acid is nucleotides
and when combined together forms a
polynucleotide which is the major component
of nucleic acid

6. Nucleotide
 Components of nucleotide:
o Nitrogenous bases
o Sugar
o Phosphate group

7. Nitrogenous Bases
Classified into:
 Purines: are bases such as Adenine and
Guanine
 Pyrimidines: are bases such as Cytosine,
Thymine and Uracil

8. Nitrogenous Bases

9. Sugar
 The general name for the sugar component of
nucleotide is ribose
 The sugar component of RNA is D-ribose and in
DNA is 2-Deoxy-D-ribose
 The combination of sugar and nitrogenous base
is known as nucleoside

10. Sugar

11. Nucleoside
Base Sugar Nucleoside
Adenine Deoxy-D-ribose Deoxyadenosine
Guanine Deoxy-D-ribose Deoxyguanosine
Thymine Deoxy-D-ribose Deoxythymidine
Cytosine Deoxy-D-ribose Deoxycytidine

12. Nucleoside
Base Sugar Nucleoside
Adenine D-ribose Adenosine
Guanine D-ribose Guanosine
Uracil D-ribose Uridine
Cytosine D-ribose Cytidine

13. Phosphate Group
 Is the third component of
nucleotide
 When phosphate group
bond to -C𝐻2OH of a
nucleoside, the result is
nucleotide

14. Two Major Types of Nucleic Acids

15. Deoxyribonucleic Acid
 Is the genetic material
found in all living
organisms
 Composed of two strands

16. Ribonucleic Acid
 Mostly involved in protein
synthesis
 Composed of one strand

17. Structure of Nucleic Acid
 The primary structure is the sequence of
nucleotides itself which has two parts: the
backbone of the molecule and the bases that
are the side chain group
 The backbone of DNA consists of sugar and
phosphate group

18. Structure of Nucleic Acid
 The backbone has 2 ends: a 3’
–OH end and a 5’ –OH end
 Nitrogenous bases are the
side chain

19. Structure of Nucleic Acid
 The secondary structure of DNA
is the established 3 –
dimensional structure
 DNA is composed of 2 strands
entwined around each other in a
double helix
 Bidirectional: Leading and
Lagging Strands

20. Types of RNA
 Messenger RNA (mRNA)
Carry the genetic information
from DNA in the nucleus
directly to the cytoplasm
 Ribosomal RNA (rRNA)
Ensures the proper alignment
of mRNA and ribosomes

21. Types of RNA
 Transfer RNA (tRNA)
Carries the correct amino
acid to the site of protein
synthesis

22. Central Dogma

23. Central Dogma
 Transcription: DNA-RNA
 Translation: RNA-codon of amino acid
 In complementary base pairing, A, T, G and C
on the template DNA strand specify U, A, C and
G respectively, on the RNA strand being
synthesized

24. Sample problems
1. What amino acid sequence is produced from the
RNA sequence: ACGAAAGAA?
2. Using the codon chart, what is the sequence of
amino acids that is produced when CCAAGCTCT
is translated? (hint: CCAAGCTCT is a DNA
sequence)
3. How many codons are present in the sequence:
AUGCCGAAACGU?

25. Sample problems
4. What amino acids are produced from the codon
sequence AUGCCGAAACGU?
5. The sequence of a short DNA segment is
ATGGCAATA. What would be the sequence of the
complementary strand after transcription and
translation?
6. What is the corresponding RNA sequence of the DNA
strand: GCTTTTCAAAAA?

26. Sample problems
7. What is the codon sequence of the DNA
sequence; GCTTTTCAAAAA?
8. Using the codon chart, what is the sequence of
amino acids that is produced when the DNA
sequence AGCCAATGC is translated?