DNA structure/function Flashcards
(14 cards)
What does DNA stand for?
DNA stands for deoxyribonucleic acid
What does DNA code for?
DNA codes for the sequence of amino acids in the primary structure of proteins
What does the primary structure of a protein determine?
The primary structure determines the final 3D structure and function of a protein
Brief description of DNA: (two points)
DNA is a polymer with a double helix structure
What monomer makes up DNA?
Nucleotide
What is a nucleotide made up of?
A pentose sugar (deoxyribose), a phosphate group and a nitrogenous containing base (cytosine, guanine, adenine and thymine)
What is a polymer of nucleotide?
A polynucleotide
How do nucleotides join together?
Nucleotides join together through condensation reactions.
What forms the genetic code?
The nitrogenous bases form the genetic code
What is the sugar phosphate backbone?
The sugar phosphate backbone has strong covalent bonds between the sugar and phosphate groups that hold the polymer together
What does each nitrogenous base pair with?
Adenine and thymine forms a hydrogen bond
Guanine and cytosine form a hydrogen bond
How many hydrogen bonds are formed between each nitrogenous base?
Adenine and thymine forms 2 hydrogen bonds
Whereas cytosine and guanine form three hydrogen bonds
Why are the complementary base pairs important?
The complementary base pairing is important to help maintain the order of the genetic code when DNA replicates
How does the structure relate to function?
- DNA being a large molecule enables it to carry lots of information
- The hydrogen bonds are weak so when DNA replication occurs the bonds will be easily broken and the replication of DNA can easily be done
- DNA has a stable structure due to the phosphodiester bonds which create the sugar phosphate backbone. This structure means the strong covalent bonds are in the outside of he helix, leaving the weaker hydrogen bond so the middle of the helix protected
