Replication Flashcards
1
Q
What is DNA replication?
A
- the process of making a new DNA molecule from an existing DNA molecule that is identical to the original molecule
2
Q
When and where does DNA replication take place?
A
- in the nucleus
- during the interphase (in between cell divisions) in the cycle of a cell
3
Q
Why is replication necessary?
A
- DNA needs to produce another molecule exactly the same as itself
- to ensure that the genetic code is passed on to each new daughter cell formed during cell division
4
Q
What is the 1st step of replication?
A
- The process is catalysed by the enzyme DNA polymerase
5
Q
What is the 2nd step of replication?
A
- The double helix unwinds
6
Q
What is the 3rd step of replication?
A
- The weak hydrogen bonds holding the base pairs together break, allowing the two strands to part
7
Q
What is the 4th step of replication?
A
- Each single chain of bases is exposed
8
Q
What is the 5th step of replication?
A
- Free nucleotides in the cytoplasm become attached to their matching, exposed base partners
9
Q
What is the 6th step of replication?
A
- The fact that A will only bond with T, and C only with G, makes sure that the sequence of the bases in the daughter DNA is exactly the same as in the parent DNA. One DNA double helix therefore becomes 2 identical double helices
10
Q
What is the 7th step of replication?
A
- The two daughter DNA molecules each twist to form a double helix which then winds itself around the histones (proteins), forming a chromosome.
11
Q
How long does the whole procedure of DNA replication take?
A
- only a couple of seconds
