Nucleic Acids

• What are nucleic acids?

  Biological molecules carrying genetic information
• What are the two types of nucleic acids?

  DNA and RNA
• What is the primary function of DNA?

  Stores genetic information and codes for proteins
• What is the role of RNA?

  Transports genetic information from DNA
• What are the monomers of nucleic acids called?

  Nucleotides
• What are the three basic components of nucleotides?

  Phosphate group, pentose sugar, nitrogenous base
• Why do nucleic acids have an overall negative charge?

  Due to the negative charge of phosphate groups
• What is a pentose sugar?

  A 5-carbon sugar
• What are the pentose sugars found in DNA and RNA?

  Deoxyribose in DNA, ribose in RNA
• What is the significance of the hydroxyl group on ribose?

  It makes ribose good for transport
• Name the five nitrogenous bases.

  Adenine, thymine, uracil, guanine, cytosine
• What bases are found in DNA?

  A, C, G, T
• What bases are found in RNA?

  A, C, G, U
• What are the two structures of nitrogenous bases?

  Purines and pyrimidines
• Which nitrogenous bases are purines?

  Adenine and guanine
• Which nitrogenous bases are pyrimidines?

  Cytosine, thymine, and uracil
• What is a condensation reaction in nucleic acids?

  • Joins nucleotides via phosphate and sugar
  • Forms covalent phosphodiester bonds
  • Creates sugar-phosphate backbone
• What is the bond formed in a condensation reaction between nucleotides?

  Phosphodiester bond
• What is the sugar-phosphate backbone?

  Chain of phosphate groups and sugars
• How are two mononucleotides joined together?

  Through a condensation reaction
• Describe the structure of DNA.

  • Two polynucleotide strands
  • Antiparallel orientation
  • Held together by hydrogen bonds
  • Complementary base pairing
  • Forms a double helix
• What base pairs with guanine in DNA?

  Cytosine
• What base pairs with adenine in DNA?

  Thymine
• Describe the structure of RNA.

  • Single-stranded polynucleotide
  • Contains uracil instead of thymine
  • Has ribose sugar
  • Shorter than DNA chains
• What is the START codon sequence?

  AUG
• How many codons are there in most organisms?

  64 codons
• What is a codon?

  A sequence of three bases coding for amino acids
• What does it mean that codons are non-overlapping?

  Each base is read once, no overlaps
• What does it mean that codons are degenerate?

  Multiple codons can code for the same amino acid
• What is the significance of the genetic code being universal?

  It is the same in almost all living organisms
• What is a gene?

  A sequence of bases coding for amino acids
• Describe the differences between DNA and RNA.

  • DNA: double-stranded, deoxyribose, thymine
  • RNA: single-stranded, ribose, uracil
• What is the role of hydrogen bonds in DNA?

  They hold the polynucleotide chains together
• How do the two strands of DNA run?

  In opposite directions, antiparallel
• What is the function of the STOP codons?

  Signals the end of a polypeptide chain
• How does the degenerate nature of the genetic code limit mutations?

  It reduces the impact of mutations on proteins
• What is the significance of the sequence AUG?

  It is the START codon for protein synthesis
• What does a gene control?

  Protein structure and function
• What is the relationship between genes and polypeptide chains?

  Genes code for sequences in polypeptide chains
• How are bases joined together in nucleic acids?

  Through hydrogen bonds between complementary pairs