Nucleotides and Nucleic Acids

• What are nucleotides?

  Monomers of nucleic acids
• What nitrogenous bases are purines?

  Adenine and guanine
• What nitrogenous bases are pyrimidines?

  Cytosine, thymine, and uracil
• What sugar is found in RNA?

  Ribose
• What sugar is found in DNA?

  Deoxyribose
• What is the role of phosphate groups in ATP?

  Energy transfer in metabolism
• What is ATP made from?

  ADP and inorganic phosphate
• What enzyme synthesizes ATP?

  ATP synthase
• What is the process of breaking down ATP called?

  Hydrolysis
• What is the result of ATP hydrolysis?

  ADP and inorganic phosphate
• What is the primary structure of a protein determined by?

  Sequence of amino acids
• What is the structure of DNA?

  Double helix with anti-parallel strands
• What bonds hold the two DNA strands together?

  Hydrogen bonds between complementary bases
• What is the sugar-phosphate backbone in DNA?

  Formed by phosphodiester bonds
• What is the advantage of DNA being double-stranded?

  Both strands can act as templates
• What is the significance of weak hydrogen bonds in DNA?

  They require little energy to break
• What is the process of DNA replication?

  Copying DNA to create new strands
• What is the role of DNA helicase in replication?

  Breaks hydrogen bonds between bases
• What enzyme joins adjacent DNA nucleotides?

  DNA polymerase
• What are the three special features of the genetic code?

  Degenerate, universal, and non-overlapping
• What does it mean that the genetic code is degenerate?

  More than one triplet codes for an amino acid
• Why is the genetic code universal?

  Same triplet codes for the same amino acid in all organisms
• What does non-overlapping mean in the genetic code?

  Each base is part of only one codon
• What are introns and exons?

  Introns do not code; exons do code
• What happens to introns during mRNA processing?

  They are spliced out
• What initiates translation in protein synthesis?

  Start codon on mRNA
• What ends translation in protein synthesis?

  Stop codon on mRNA
• What is the role of RNA polymerase in transcription?

  Joins RNA nucleotides to form mRNA
• What is the process of transcription?

  Creating mRNA from a DNA template
• What happens to mRNA after transcription?

  It leaves the nucleus for the cytoplasm
• What is the role of ribosomes in protein synthesis?

  Site of translation for polypeptide formation
• What is the significance of codons in mRNA?

  Each codon codes for a specific amino acid
• What is the structure of tRNA?

  Single-stranded with a cloverleaf shape
• What is the role of tRNA in protein synthesis?

  Transfers specific amino acids to ribosomes
• What is semiconservative DNA replication?

  One old strand and one new strand are formed
• What is the role of DNA polymerase in replication?

  Joins nucleotides to form new DNA strands
• What is the significance of the three prime and five prime ends in DNA?

  Indicates directionality of the DNA strands
• What is the function of the enzyme DNA helicase?

  Unwinds the DNA double helix
• What is the role of free-floating nucleotides in DNA replication?

  Align opposite their complementary bases
• What is the advantage of the genetic code being universal?

  Facilitates genetic engineering across species