The slides also contain a short historical background on DNA; concepts on DNA replication and protein synthesis; and sample activities for DNA replication and protein synthesis.

2. What is DNA?
➢ A type of nucleic acid
➢ Basis for inheritance
➢ Its structure is proposed by
James Watson and Francis
Crick

3. HISTORICAL BACKGROUND
As Genetic Material
Gregor Mendel
Introduced the basis of inheritance
More scientists wanted to know the source of
genetic information

4. As Genetic Material
Alfred Hershey and Martha Chase
Confirmed that DNA and not the
protein is the genetic material

5. Its Composition
Phoebus Levene
Identified the basic structure of a DNA
nucleotide
Erwin Chargaff
Explained the base- pairing in DNA
(Chargaff’s Rule)

6. Its Structure
Rosalind Franklin
Her data collected became helpful in
identifying the structure of DNA
Watson & Crick
Created the very first 3D model of the
DNA

7. DNA Structure ➢ a polymer composed
of nucleotides
❑ Nitrogenous Base
➢ Guanine
➢ Cytosine
➢ Adenine
➢ Thymine
❑ 5-Carbon Sugar
(deoxyribose)
❑ Phosphate Group

8. DNA Structure ❑ Purine bases
(2 rings)
✓ Guanine (G)
✓ Adenine (A)
❑ Pyrimidine
bases (1 ring)
✓ Cytosine (C)
✓ Thymine (T)

10. Replication

11. DNA Replication
➢Fundamental process occurring in
all cells
➢Each cell must replicate its DNA
before division

12. Why do
cells need
to
replicate
their DNA
before
mitosis?

13. How DNA Replicates?

14. ➢ Semi discontinuous
➢Leading strand (continuous)
➢Lagging strand (fragments)
✓Okazaki fragments
✓joined by ligases

15. Steps in DNA Replication
1. Unwinding
- DNA helicase
2. Base pairing
- DNA primase
- DNA polymerase
3. Joining
- DNA ligase

16. Base pairing
C G G A C C G
G C C T G G C

17. Practice
A G C T C G A
T C G G C T
A
C T T A G A C
G A A T C T G

18. More practice
1. C C G C T T T C G C T A T
2. T A T A G A C A G G G C T
Write down the complementary base
pair of the following DNA sequence
GG C G
A
A A G C G A T A
A T
A
T C T G T C C C G A

19. 3. A T A A C T A A A C G A G
4. G A T C G A C G A A T G C
5. C A G C T T C G A C T C A

20. Activity
AT: DNA Replication
LT: Identify the components of DNA
Write the complementary base pair
of a DNA sequence

21. A. Identify the numbered parts.
1.
2.
3.
4.

22. B. Write the complementary pair.
5. A C A C A T T C G C T G G
6. G A G T C C G A G G C T A
7. T A A C A C C C G T G G T

23. 8. C C G T G A T C G G A A T
9. G G G C C G T T A A A G A
10. C T T T A T G C G C C G

24. Protein
Synthesis

25. Basis DNA RNA
Number of strands Two (2) One (1)
Sugar Deoxyribose Ribose
Nitrogen bases C G T A C G U A
Location nucleus
nucleus,
cytoplasm

26. 1.Transcription
- takes the information
from DNA and encodes it into
mRNA, which heads out of the
cell’s nucleus and into the
cytoplasm

27. 2. Translation
- the mRNA works with a
ribosome and tRNA to
synthesize proteins

28. In summary…
Transcription
DNA Translation
RNA Protein
mRNA
Codon Anticodon
tRNA

29. How is it
done?

31. U G U U C U G C C A U G A C U
A C A A G A C G G U A C U G A
Cysteine Serine Methionine
Alanine Threonine
(codon)
(anticodon)

32. A G G C G C G U C U C G A U C
(codon)
(anticodon)
U C C G C G C A G A G C U A G
Arginine Arginine Valine Serine Isoleucine

33. T A C G C A C T T G G G C T A A A A A C T
(codon)
(anticodon)
Practice:

34. Activity
AT: Protein Synthesis
LT: To write the process of protein
sysnthesis

35. A T G A T A A C G C T A C A A G A T T G A
A.
(codon)
(anticodon)

36. A T G G C A C T T G G G C T A A A A T A G
(codon)
(anticodon)
B.

37. 1.
3.
5.
4.
6.
2.
Cysteine Serine Alanine Methionine
7. Threonine
8. 9.
(codon)
(anticodon)
C.