DNA Structure and Replication

Created by

Harry Dias

Cards (20)

What does DNA stand for?
Deoxyribonucleic Acid
What does RNA stand for? 
Ribonucleic Acid
What are Genes? 
Lengths of DNA that code for a specific Protein
Both DNA and RNA are Polynucleotides, however... 
DNA is made of two Polynucleotide Strands and RNA is made of one Polynucleotide Strand
What are the 3 components of a Nucleotide?
Pentose Sugar (5 Carbon Sugar)
Phosphate Group
Nitrogenous Base
What is the Pentose Sugar in DNA called? 
Deoxyribose Sugar
What is the Pentose Sugar in RNA called? 
Ribose Sugar
What Nitrogenous Base is different in RNA and DNA 
Uracil and Thymine
What Nitrogenous Bases are Pyramidines (Single Ring)? 
Thymine - T
Cytosine - C
Uracil - U
What Nitrogenous Bases are Purines (Double Ring)? 
Adenine - A
Guanine - G
What is the bond between a Phosphate Group and a Pentose Sugar called? 
Phospodiester Bond
How is a Phosphodiester Bond formed? 
By condensation reaction
How many hydrogen bonds do A T and A U have? 
2
How many hydrogen bonds do C G have? 
3
Why do some nitrogenous bases have different amounts of hydrogen bond? 
To keep the two strands parallel to form double helix
Structure of DNA 
Polymer of Nucleotides
Each Nucleotide is formed from Deoxyribose, a Phosphate Group and a Nitrogenous Base
Has Phosphodiester Bonds between Nucleotides
Two strands held by Hydrogen Bonds to form a Double Helix
Hydrogen Bonds between Adenine, Thymine AND Guanine, Cytosine
Histone 
Protein associated with DNA in Chromosomes
DNA Helicase 
Breaks down Hydrogen Bonds between AT and CG
DNA Polymerase 
Joins adjacent DNA Nucleotides
Catalyses Condensation Reactions in the formation of Phosphodiester Bonds between adjacent Nucleotides
Features of DNA that are important in Semi-Conservatative Replication
Weak Hydrogen Bonds make it easy to separate strands of DNA
Two strands can be used as two templates
Complementary Base Pairing allows for accurate DNA Replication