1. DNA Replication

2. DNA Replication Replication = DNA copies itself exactly
(Occurs within the nucleus)
Any mistake in copying = mutation
DNA mutation = chromosomal mutation

3. A. Basic Facts of DNA Replication
1. Complementary base pairing
makes replication possible
C - G
A - T

4. A. Basic Facts of DNA Replication
2. One side of DNA molecule is a template for making the other side (strand)
?’s 1-3

5. B. Process of DNA Replication
Uncoil & unzip DNA molecule
Enzyme (-ase) breaks
weak Hydrogen Bond
between bases

6. B. Process of DNA Replication
2. Enzyme brings in complementary N-bases
DNA Replicase

7. B. Process of DNA Replication
3. Insert N-bases
DNA Replication Tutorial
(Go here for on-your-own learning/review)
trc.ucdavis.edu/.../week5/06dnareplication.html

8. Replication Movie
C - G
A - T

9. C. Semi-conservative replication
Each new DNA molecule
contains
one old strand
&
one new strand
?’s 4-6

11. ** DNA Polymerase adds bases in a 5 prime to 3 prime direction,
so lagging strand needs a primer to start

13. DNA Polymerase Works in 5’ to 3’ Direction

14. Steps of DNA Replication
1. Helicase unzips and unwinds DNA
2. Topoisomerase keeps DNA from becoming tangled
** Leading Strand: works from 5’ to 3’
DNA Polymerase adds bases to old strand
** Lagging Strand
DNA Polymerase cannot not directly bind because works from 5’ to 3’ direction, so DNA primase brings an RNA primer, which then sets up the DNA so DNA Polymerase can begin to add bases.
This happens in sections called Okazaki fragments that are later glued together by DNA ligase.

15. Song: https://www. youtube. com/watch
Song: Animation: