3.8 Nucleic Acids Flashcards
2 types of nucleic acids
RNA
DNA
Elements in nucleic acids
Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorous
Monomers in nucleic acids
Nucleotides
Components of nucleotides
Pentose monosaccharide
Phosphate group PO42-
Nitrogenous base
How are nucleic acids formed?
Condensation reactions
Phosphate group at 5th carbon of pentose sugar of one nucleotide forms a covalent bond with the hydroxyl group at the 3rd carbon
Formation of phosphodiester bonds
How are nucleic acids formed?
Condensation reactions
Phosphate group at 5th carbon of pentose sugar of one nucleotide forms a covalent bond with the hydroxyl group at the 3rd carbon
Formation of phosphodiester bonds
Bases in DNA
Adenine
Thymine
Cytosine
Guanine
Pyrimidines
Smaller bases - single carbon ring
Cytosine and Thymine
Purines
Larger bases - double carbon ring
Adenine and Guanine
Why are DNA strands antiparallel?
Two strands run in opposite directions
Complementary base pairing
A-T (2 hydrogen bonds)
C-G (3 hydrogen bonds)
Role of RNA
Transfer of genetic information from DNA to proteins
RNA vs DNA
Pentose sugar in RNA is ribose, DNA has deoxyribose
Uracil in RNA, Thymine in DNA
RNA is small enough to leave the nucleus, but DNA is not
What happens to RNA after protein synthesis?
Degraded in the cytoplasm
RNA nucleotides are released and reused
DNA extraction
Grind sample in pestle and mortar - break down cell walls
Mix with detergent - break down cell membranes
Add salt - breaks hydrogen bonds between DNA and water molecules
Add protease - break down histone proteins
Add ethanol layer - causes DNA to precipitate out of the solution
