DNA vs RNA

1. University of Duhok
College of Health Sciences
Dep. of Medical Laboratories & Anesthesia
Biology/1st Stage
Lecture 6
Dr.: Shameeran S. Ismael
BVM & S, M.Sc Medical Microbiology(Parasitology),
PhD Molecular Parasitology

2. DNA vs. RNA Structure and
Function

3. There are two types of Nucleotides
(depending on the sugar they contain)
1- Deoxyribonucleic acids (DNA):
The pentose sugar is Deoxyribose (has just an
hydrogen in the same place--- H)
Deoxy = “minus oxygen
2. Ribonucleic acids (RNA):
The pentose sugar is Ribose (has a hydroxyl
group in the 3rd carbon---OH)

4. Nucleotides and Nucleosides
• Nucleotide:
 Nitrogeneous base
 Pentose
 Phosphate
• Nucleoside :
 Nitrogeneous base
 Pentose
• Nucleobase:
 Nitrogeneous base

5. Base（purine、pyrimdine）+ribose（deoxyribos
N-glycosyl linkage
nucleoside+phosphate
phosphoester linkage
nucleotide
phosphodiester linkage
nucleic acid

6. • DNA is a very large molecule made up of a long
chain of sub-units. The sub-units are called
nucleotides. Each nucleotide is made up of: a
sugar called deoxyribose, a phosphate group -PO4
and
• Genes:A gene is a small region in the DNA.
What is DNA?

7. I.Deoxyribonucleic Acid (DNA):
Nucleus
Chromosomes
Genes
Segments of
DNA
Portions of DNA are
called genes.
DNA is tightly wound
into chromosomes and
located in the nucleus
of cells.
DNA cannot leave the
nucleus.
DNA is double
stranded (2 sides)
an organic base

8. Functions of
Nucleotides and Nucleic Acids
• Nucleotide Functions:
 Energy for metabolism (ATP)
 Enzyme cofactors (NAD+)
 Signal transduction (cAMP)
• Nucleic Acid Functions:
 Storage of genetic info (DNA)
 Transmission of genetic info (mRNA)
 Processing of genetic information (ribozymes)
 Protein synthesis (tRNA and rRNA)

9. II.Ribonucleic Acid (RNA):
RNA is single stranded and does not
have to stay in the nucleus!
RNA is not found in chromosomes
because it does not carry the genetic
code, however it can read the DNA
code and take the information out
of the nucleus.
RNA’s main job is to build
proteins!

10. Structure of DNA
The building blocks of DNA are
called Nucleotides.
One nucleotide is made of 3
important things:
1. 5-Carbon Sugar Deoxyribose
2. Phosphate
3. Nitrogen base
There are 4 nitrogen bases in DNA:
Adenine, Guanine, Cytosine, and
Thymine that pair together)
A  T C G

11. DNA Nitrogen Bases
• Four bases are:
–Thymine
–Adenine
–Cytosine
–Guanine

12. Adenine (A)
always pairs
with Thymine
(T)
Cytosine (C)
always pairs
with Guanine
(G)

13. • Ribonucleic Acid
• Created from DNA replication
• Single-strand
• Uracil base instead of Thyamine base
• Ribonucleic acid
– Uses ribose instead of deoxyribose
What is RNA used for?
For protein synthesis
What is RNA?

14. Structure of RNA
The building blocks of RNA are
Nucleotides, just like DNA.
A Nucleotide in RNA is still made of 3
important things:
1. 6-Carbon Sugar - Ribose (instead of
Deoxyribose)
2. Phosphate
3. Nitrogen base
there are 4 nitrogen bases in RNA,
A,G,C, and U that pair together)
A  U C G

15. DNA vs RNA

16. Nitrogenous bases
Sugar-phosphate
backbones
Thymine
(T)
Adenine
(A)
Cytosine
(C)
Guanine
(G)
PurinePyrimidines
Hydrogen bonds
Nitrogenousbases
5
35
3
Uracil (U)

17. Repeated Sugar - Phosphate
Sugar–Phosphate-Base
Polynucleotide
DNA backbone
One nucleotide
DNA Molecule
DNA Double stranded
RNA single stranded
T C G A T A G
A G TC T A C
UUmRNA
DNA

18. Types of RNA
1. Messenger RNA (mRNA): Carries copies of
instructions for the assembly of amino acids
into proteins from DNA to the rest of the cell
(serve as “messenger”)

19. 2.Ribosomal RNA (rRNA): Makes up the major
part of ribosomes, which is where proteins are
made.
Ribosomal
RNA

20. 3. Transfer RNA (tRNA): Transfers amino
acids to ribosomes during protein
synthesis

21. • Protein Synthesis
What is RNA used for?

22. Thanks for attention, please check
UOD Moodle and Google classroom