Nucleic Acids-Semi Conservative Replication Flashcards
What are the 2 reasons for DNA replication?
-Cell Division-Reproduction
Why does DNA need to replicate for Cell Division?
New Cells need new DNA for growth and tissue repair.
Why does DNA need to replicate for Reproduction?
Gametes requires DNA to pass on genetic information.
What is the first step in semi-conservative replication?
Hydrogen bonds break
What is the second step in semi- conservative replication?
The molecule is unzipped
What is the third step in semi- conservative replication?
Free nucleotides join the unpaired bases
What is the fourth step in semi- conservative replication?
Hydrogen Bonds forms between base pairs.
What is the fifth step in semi- conservative replication?
Phosphodiester bonds form between nucleotides.
Why is is called semi-conservative replication?
Half of the molecules is old DNA (template) and the other half is made of new molecules.
What does DNA Helicase do?
Breaks hydrogen bonds and unzips the molecule.
What does DNA Polymerase do?
Forms the phosphodiester bonds between nucleotides.
Which direction does DNA Polymerase work?
5’ to 3’
What does DNA Ligase do?
Joins two fragments of DNA to form a longer strand of DNA
Which end is the strand unzipped from in Continuous Replication?
3’ end
What is meant by continuous replication?
Can be continuously replicated as the strands unzips.
What strand is on continuous replication?
Leading Strand
Which end is the strand unzipped from in Discontinuous Replication?
5’ end
What is meant by discontinuous replication?
DNA polymerase has to wait until a section of the strand has unzipped then work back along the strand.
What are the sections called in which the DNA are produced in?
Okazaki Fragments
What strand is on discontinuous replication?
Lagging Strand
What are the two types of substitution mutations?
Transition and Transversion
What is Transition Mutation?
Where one pyrimidine is swapped for a different pyrimidine or a purine for a purine.
What is Transversion Mutation?
Where one pyrimidine is swapped for a purine or vice versa.
What is Silent Mutation?
The triplet codes for the same amino acid.
What is a Missense Mutation?
The triplet codes for a different amino acid.
What is a Nonsense Mutation?
The triplet code for a stop codon.
Insertion or Deletion are examples of…
Frameshift.
If the mutation is closer to the beginning of the gene, how will it change the gene?
Be more altered if it is closer to the beginning.
Where does Silent, Missense or Nonsense mutation occurs?
If substitution occurs in a region of the gene involved in coding.
