3.8 Nucleic Acids Flashcards
What is a polynucleotide (nucleic acid)?
A polymer of monomers called nucleotides
What are the three components that make up a nucleotide?
-A pentose sugar containing 5 carbon atoms
-A phosphate group (PO4 2-)
-A nitrogenous base
How are individual nucleotides joined together?
-Through a condensation reaction to form a polymer called a polynucleotide
-The phosphate group at the 5th carbon of the pentose sugar (5’) of one nucleotide forms a covalent bond with the hydroxyl OH group at the carbon 3’ of the pentose sugar of an adjacent nucleotide known as a phosphodiester bond
-This forms a long, strong sugar-phosphate ‘backbone’ with a base attack head to each sugar
What elements do nucleotides contain?
Carbon, Hydrogen, Nitrogen, Phosphorus
What are the bonds called in a polynucleotide?
phosphodiester bonds
How are phosphate bonds broken down?
-Through a hydrolysis reaction, releasing the individual nucleotides
Draw the base structure of a nucleotide and its three components
What does DNA stand for?
Deoxyribonucleic acid
What are the two types of nucleic acid present in all cells?
DNA, RNA
What sugar does DNA contain?
pentose sugar, deoxyribose which had one less oxygen then in ribose
What sugar does RNA contain?
pentose sugar, ribose
What is the comparison of the structure of deoxyribose in DNA and ribose in RNA?
-Both pentose sugars
-Ribose has one more oxygen than deoxyribose
What are the four different bases in DNA?
-Thymine
-Adenine
-Guanine
-Cytosine
What bases in DNA are purines?
adenine and guanine
What bases in DNA are pyrimidines?
thymine and cytosine
