Nucleic acids and enzymes

• What are nucleic acids primarily composed of?

  DNA and RNA
• How are the two DNA strands joined together?

  By hydrogen bonds between nitrogenous bases
• Which base pairs with adenine?

  Thymine
• How many hydrogen bonds form between adenine and thymine?

  Two hydrogen bonds
• Which base pairs with guanine?

  Cytosine
• How many hydrogen bonds form between guanine and cytosine?

  Three hydrogen bonds
• What analogy is used to describe the structure of DNA?

  • Twisting rope ladder
  • Pegs represent base pairs
  • Twisted ladder forms a helix
• What is the role of hydrogen bonds in DNA?

  They allow the molecule to unzip for replication
• What are the components of a nucleotide?

  Nucleotide base, sugar, and phosphate group
• What is the 5' end of a DNA strand?

  Where the phosphate group is attached to carbon 5
• What is the 3' end of a DNA strand?

  Where the phosphate group is attached to carbon 3
• What forms the rungs of the DNA ladder?

  Complementary base pairs joined by hydrogen bonds
• Why is the DNA molecule stable?

  Due to the integrity of coded information
• What is the significance of the term 'nucleotide bases'?

  They are part of a nucleotide
• What was known about DNA in the late 1800s?

  It was referred to as the 'stuff' of the nucleus
• Who contributed to the discovery of DNA structure?

  Watson, Crick, and Wilkins
• What is the first step in DNA extraction?

  Macerating the tissue
• What is used to aid in DNA extraction?

  A strong detergent like washing up salts
• What are the key features of eukaryotic DNA organization?

  • Majority in the nucleus
  • Tightly wound around histone proteins
  • Organized into chromosomes
• What are the key features of prokaryotic DNA organization?

  • DNA in a loop within cytoplasm
  • Not wound around histone proteins
  • Described as naked DNA
• What is semi-conservative DNA replication?

  Each new DNA has one old and one new strand
• What is an activated deoxynucleotide?

  Nucleotide using single-stranded DNA as template
• Why must DNA be copied during cell division?

  To ensure each new cell has full instructions
• What is the relationship between the nucleotide base sequence on one strand of DNA?

  It determines the sequence on the opposite strand
• What is the complementary base sequence for CACGTTCGGGAT?

  GTGCAAGCCCTA
• What are the ways the structure of DNA enables its function?

  • Double helix provides stability
  • Hydrogen bonds allow unzipping for replication
  • Antiparallel strands facilitate replication
  • Complementary base pairing ensures accurate copying