Unit 5: The Central Dogma - DNA Structure & Replication Flashcards
What does DNA stand for?
Deoxyribonucleic Acid
What are the monomers of DNA?
Nucleotides
What are the three parts of nucleotides?
Phosphates, deoxyribose sugars, and nitrogen bases.
What are the four different nucleotides?
Guanine, Adenine, Cytosine, and Thymine.
Which nucleotides are purines?
Guanine and Adenine
What does it mean if a nucleotide is a purine?
The nucleotide has two rings.
Which nucleotides are pyramines?
Cytosine and Thymine
What does it mean if a nucleotide is a pyramine?
The nucleotide has one ring.
Why is DNA in the shape of a double-helix?
Pyramines always bond with purines.
Which nucleotide does Adenine bind to?
Thymine
Which nucleotide does Thymine bind to?
Adenine
Which nucleotide does Cytosine bind to?
Guanine
Which nucleotide does Guanine bind to?
Cytosine
In which phase does DNA replication take place?
The “S Phase” is where DNA replication takes place.
What does semi-conservative mean?
It means that the DNA is composed of one strand of parent DNA and one strand of newly synthesized DNA.
What are the six enzymes needed for DNA replication?
Helicase, Topoisomerase, Primase, DNA Polymerase, Exonuclease, and Ligase.
What does Helicase do?
It unzips the DNA, creating 2 single strands of DNA.
What does Topisomerase do?
It relaxes the coiled DNA.
What does Primase do?
It primes the DNA, creating a starting point for DNA polymerase.
What does DNA Polymerase do?
It is a builder, and synthesizes new strands of DNA by adding nucleotides.
What does Exonuclease do?
It cuts out RNA primers.
What does Ligase do?
It fills in the any holes and gaps, joining together DNA.
What are the seven steps of DNA replication?
Unzipping, Stabilizing, Priming, Building and Extending, Replacing, Gluing, and Proofreading.
What happens in “Unzipping”?
Helicase unzips the double-stranded DNA by breaking the hydrogen bonds between base pairs.
