• monomer = nucleotides
• elements present: C,H,O,N,P
• 3 parts of nucleotide: 5 carbon sugar (deoxyribose or ribose), phosphate group, nitrogenous bases

Nitrogenous Bases

• adenine: purine
• guanine: purine
• cytosine: pyrimidine
• thymine (DNA) or uracil (RNA): pyrimidine
  • purines: have two rings
  • pyrimidines: have one ring
  • pyramids have one base
• bonded together by phosphodiester bonds
• Grows at 3’ end
• Read and Changed from 5’ to 3’
• Functions of nucleotides
  • energy source (ATP)
  • H+ ion and electron carrier (NADH, NADPH, FADH2)

Nucleic acids are the reason for heredity and code for the amino acids in proteins

DNA and RNA

Comparison Chart

Directionality

• determined by the 3' and 5' ends
• replication, transcription, and translation all occur 5' to 3'
• DNA has two anti-parallel strands, so one is 5' to 3' and the other is faced 3' to 5'. BUT all processes still occur 5' to 3'.