DNA Structure and Function Flashcards
What does DNA stand for?
Deoxyribonucleic acid.
What is the function of DNA?
DNA codes for the sequence of amino acids in the primary structure of a protein which determines the final 3D structure and function of a protein.
Is DNA a polymer or monomer?
Polymer
What are the monomers of DNA?
Nucleotides
What is the structure of DNA?
Double helix.
What are DNA nucleotides made up of?
Deoxyribose (Pentose sugar)
Phosphate group
Nitrogenous base
What are the 4 nitrogenous bases for DNA?
Cytosine
Guanine
Thymine
Adenine
What are the polymers of nucleotides called?
Polynucleotides.
How are phosphodiester bonds formed?
Condensation reaction between the phosphate group and the deoxyribose sugar.
Describe phosphodiester bonds.
Strong covalent bonds that ensure the genetic code is not broken down.
What do the bases do?
Form the genetic code.
What is a sugar-phosphate backbone?
The strong covalent bonds that hold the polymer together.
How are the pairs in DNA joined together?
Hydrogen bonds between the complementary bases.
How is the double helix structure formed?
The pairs in DNA twist to form it.
What are the complementary bases?
Adenine - Thymine
Guanine - Cytosine
How many hydrogen bonds can guanine and cytosine have?
3
How many hydrogen bonds can adenine and thymine have?
2
Why is complementary base pairing important?
To help maintain the order of the genetic code when DNA replicates.
What are the 4 ways in which the structure of DNA links to its function?
Large molecule - carries a lot of information.
Complementary base pairing - allows identical copies to be made.
Weak hydrogen bonds - allows for easy unzipping of the two strands in a double helix during replication.
Stable structure - sugar phosphate backbone.
How does the sugar phosphate backbone lead to the stable structure of DNA?
It causes the strong covalent bonds to be on the outside and protect the hydrogen bonds in the inside.
