Protein Synthesis

• What is the process by which a segment of DNA is copied into mRNA?

  Transcription
• What enzyme is responsible for synthesizing RNA from a DNA template?

  RNA Polymerase
• What are the steps of transcription?

  1. Initiation: RNA polymerase binds to the promoter.
  2. Elongation: RNA polymerase unwinds DNA and synthesizes RNA.
  3. Termination: RNA polymerase reaches a termination sequence.
• What is a gene?

  A segment of DNA with instructions for proteins
• What is the name of the molecule that is a copy of the DNA gene?

  mRNA (messenger RNA)
• What enzyme is needed to make the mRNA copy?

  RNA polymerase
• How does RNA polymerase synthesize RNA during transcription?

  It unwinds DNA and synthesizes RNA in 5' to 3'
• What is the role of hydrogen bonding in transcription?

  It ensures complementary base pairing
• What are the base pairing rules during transcription?

  A pairs with U, C pairs with G
• What nucleotide pairs with Cytosine in mRNA?

  Guanine (G)
• What nucleotide pairs with Guanine in mRNA?

  Cytosine (C)
• What nucleotide pairs with Thymine in mRNA?

  Adenine (A)
• What nucleotide pairs with Adenine in mRNA?

  Uracil (U)
• Why does the DNA template strand remain unchanged during transcription?

  To conserve genetic information
• What are somatic cells?

  Non-dividing body cells
• What is gene expression?

  Not all genes are expressed simultaneously
• What process regulates gene expression by controlling mRNA production?

  Transcription
• What is translation?

  The process of synthesizing polypeptides from mRNA
• What is a sequence of amino acids called?

  Polypeptide
• What role does mRNA play in translation?

  It carries the genetic code to the ribosome
• What are ribosomes composed of?

  rRNA and proteins
• How many subunits make up a ribosome?

  Two
• Which ribosomal subunit does mRNA bind to?

  Small subunit
• Which ribosomal subunit do tRNAs bind to?

  Large subunit
• What are the three types of RNA?

  • mRNA (messenger RNA)
  • tRNA (transfer RNA)
  • rRNA (ribosomal RNA)
• What is a codon?

  A sequence of three nucleotides on mRNA
• What is an anticodon?

  A sequence of three nucleotides on tRNA
• If the mRNA codon is CGA, what is the anticodon on tRNA?

  GCU
• What are the features of the genetic code?

  • Triplet Code: Each codon has three nucleotides.
  • Degeneracy: Multiple codons can code for the same amino acid.
  • Universality: The genetic code is nearly universal across organisms.
• What is the term for multiple codons coding for the same amino acid?

  Degeneracy
• What is the term for the genetic code being the same across all organisms?

  Universality
• How can students use a codon table?

  To determine the amino acid sequence from mRNA
• What is the amino acid sequence for the mRNA: AUG CCC GGU ACC UAG?

  Methionine - Proline - Glycine - Threonine - Stop
• What is elongation in the context of translation?

  The ribosome adds amino acids to the polypeptide
• What forms between amino acids during translation?

  Peptide bonds
• What is a point mutation?

  A change in a single nucleotide in DNA
• How can a point mutation affect a protein?

  It can alter the amino acid sequence
• What disease is caused by a point mutation in the hemoglobin gene?

  Sickle cell anemia
• How does the diversity of proteins produced contribute to cell functioning?

  • Allows for a wide range of functions
  • Catalyzes reactions (enzymes)
  • Provides structural support (collagen)
• What biological processes depend on hydrogen bonding?

  • DNA replication
  • Transcription
  • Translation