Nucleic Acids Flashcards
Name two examples of nucleic acids
1.DNA
2.RNA
What is the monomer called that makes up nucleic acids?
Nucleotides
What are the three components that make up a nucleotide?
Phosphate group
Pentose sugar
Nitrogenous base
What is the polymer of a nucleic acid?
Polynucleotide chain
What type of reaction joins nucleotides together?
Condensation reaction
What is formed in the condensation reaction between nucleotides
Polynucleotide + Water
What type of reaction will break a polynucleotide chain to form nucleotides?
Hydrolysis reaction
What is the name of the bond which forms between nucleotides in condensation reactions
Phosphodiester bond
What is a phosphodiester bond?
The bond that forms in a condensation reaction between the phosphate group on 5’ and the hydroxyl (OH) group on 3’ of nucleic acids
Draw the structure of a nucleotide
A circle for the phosphate group
A pentagon for the pentose sugar
A rectangle for the nitrogenous base
Name the five nitrogenous bases
- Adenine
- Guanine
- Cytosine
- Thymine
- Uracil
What type of bond forms between nitrogenous bases?
Hydrogen bonds
Give four differences between the nucleotides of DNA and RNA
- DNA contains the deoxyribose pentose sugar, RNA contains the ribose pentose sugar
1.DNA pentose sugar has hydrogen group on carbon 2. RNA pentose sugar has Hydroxyl group on carbon 2 - DNA is double stranded, with two antiparallel strands held together by hydrogen bonds between nitrogenous bases, the strands twist around eachother to form a double helix. RNA is single stranded
- DNA contains Thymine, RNA contains Uracil, not thymine
What are the two types of nitrogenous base?
Purines and Pyrimidines
Name the two purines
Adenine and Guanine
Name the three pyrimidines
Thymine, Cytosine, Uracil
How mnay carbon rings do purines have?
Two carbon rings
How many carbon rings do pyrimidines have?
One cabron ring
Name the complementary base pairs
Adenine + Thymine (or Uracil)
Guanine + Cytosine
How many hydrogen bonds between adenine and thymine?
Two hydrogen bonds
How many hydrogen bonds between guanine and cytosine?
Three hydrogen bonds
Describe the structure of DNA
A double stranded molecule composed of antiparallel polynucleotide strands, held together by hydrogen bonds between complementary base pairs
What causes the double-helix structure of DNA?
The polynucleotide strands twist around eachother to form the double-helix shape
Describe and explain how the four nitrogenous bases pair together
Adenine and Guanine are purines. Thymine and Cytosine are pyrimidines. Purines always bond with pyrimidines.
Adenine forms two hydrogen bonds with Thymine
Guanine forms three hydrogen bonds with Cytosine
