2.2: DNA replication Flashcards
The discovery of DNA’s structure by Watson and Crick provided evidence that what was key to DNA’s ability to replicate?
The discovery of DNA’s structure by Watson and Crick provided evidence that complementary base pairing was key to DNA’s ability to replicate
The discovery of DNA’s structure by Watson and Crick provided evidence that complementary base pairing was key to DNA’s ability to replicate.
What did scientists propose?
Scientists proposed that DNA ‘unzipped,’ as hydrogen bonds between base pairs were broken
The discovery of DNA’s structure by Watson and Crick provided evidence that complementary base pairing was key to DNA’s ability to replicate.
Scientists proposed that DNA ‘unzipped,’ as hydrogen bonds between base pairs were broken.
New polynucleotide strands could then be synthesised using what as a template?
New polynucleotide strands could then be synthesised using the originals as a template
The discovery of DNA’s structure by Watson and Crick provided evidence that complementary base pairing was key to DNA’s ability to replicate.
Scientists proposed that DNA ‘unzipped,’ as hydrogen bonds between base pairs were broken.
New polynucleotide strands could then be synthesised using the originals as a template.
Several hypotheses were then proposed as what?
Several hypotheses were then proposed as to the specific mechanism by which new strands are created
Why does DNA need to replicate?
What are reasons for DNA replication?
Reasons for DNA replication are:
- Cell division
- Reproduction
Why does DNA need to replicate?
Reasons for DNA replication are cell division - New cells need new DNA for what, and reproduction?
Reasons for DNA replication are:
- Cell division - New cells need new DNA for growth and tissue repair
- Reproduction
Why does DNA need to replicate?
Reasons for DNA replication are cell division - New cells need new DNA for growth and tissue repair, and reproduction - What require DNA to do what?
Reasons for DNA replication are:
- Cell division - New cells need new DNA for growth and tissue repair
- Reproduction - Gametes require DNA to pass on genetic information
Enzymes in DNA replication:
What does DNA helicase do?
DNA helicase:
- Breaks hydrogen bonds
- Unwinds the molecule
Enzymes in DNA replication:
What does DNA polymerase do?
DNA polymerase forms the phosphodiester bonds between nucleotides
Before a nucleus divides, what must happen?
Before a nucleus divides, its DNA must be replicated (copied)
Before a nucleus divides, its DNA must be replicated (copied).
This is to ensure what?
This is to ensure that all the daughter cells have the genetic information to produce the:
1. Enzymes
2. Other proteins
that they need
For semi-conservative replication to take place, there are how many requirements?
For semi-conservative replication to take place, there are 4 requirements:
- The 4 types of nucleotide, each with their bases of A, T, C or G, must be present
- Both strands of the DNA molecule act as a template for the attachment of these nucleotides
- The enzyme DNA polymerase
- A source of chemical energy is required to drive the process
The process of semi-conservative replication:
The enzyme what breaks the hydrogen bonds linking the base pairs of DNA?
The enzyme DNA helicase breaks the hydrogen bonds linking the base pairs of DNA
The process of semi-conservative replication:
The enzyme DNA helicase breaks the hydrogen bonds linking the base pairs of DNA.
As a result, what happens?
As a result, the double helix:
- Separates into its 2 strands
- Unwinds
The process of semi-conservative replication:
The enzyme DNA helicase breaks the hydrogen bonds linking the base pairs of DNA.
As a result, the double helix separates into its 2 strands and unwinds.
Each exposed polynucleotide strand then acts as a template to which what?
Each exposed polynucleotide strand then acts as a template to which complementary free nucleotides bind by specific base pairing