Nucleotides and Nucleic Acids

• DNA is deoxyribonucleic acid, RNA is ribonucleic acid, both nucleic acids are long, unbranched chains and polymers of nucleotides (they are polynucleotides, macromolecules)
• Nucleotide subunits are joined by phosphodiester (sugar-phosphate) bonds made by condensation reactions, a nucleotide is a nitrogen-containing organic substance that forms the basis of RNA and DNA (8 types)
• Nucleotides are made for...

  A) Phosphate group

  B) Pentose Sugar

  C) Organic nitrogenous base

  
• Cellular roles: form nucleic acids (DNA and RNA), ATP (energy storage), and metabolic reactions; respiration and photosynthesis (NAD, NADP, and coenzyme A)
• Formation of nucleotides:

  A) Condensation

  B) phosphate

  C) Five-carbon sugar

  D) Organic base

  
• Joins other nucleotides by condensation reactions (which involve carbons 3 and 5) between the phosphate group of one and the pentose sugar of another; the covalent bond formed is called a phosphodiester bond
• Bonding of many nucleotides produces a polynucleotide molecule/chain/strand; described as having a sugar-phosphate backbone, with bases sticking out to one side
• The covalent bond that is formed is called a phosphodiester bond

  A) Condensation

  B) Phosphodiester

  C) H_2O

  D) Phosphodiester

  
• Deoxyribose only has hydrogen bonded to its C2, meaning it has one less oxygen than ribose, which has a hydroxyl group attached to its C2

  A) Deoxyribose

  B) ribose

  C) OH

  D) H

  E) Pentose sugars

  
• Pyrimidines: Single-ring structure in DNA (thymine and cytosine) and RNA (uracil and cytosine); Purines: Double-ring structure in DNA and RNA (adenine and guanine)

  A) purine

  B) pyrimidine

  C) adenine

  D) guanine

  E) thymine

  F) uracil

  G) cytosine