protein synthesis

• What is the definition of transcription in the context of protein synthesis?

  Transcription is the synthesis of RNA using DNA as a template.
• What enzyme is responsible for transcribing DNA to RNA?

  RNA polymerase
• What happens when RNA polymerase attaches to the beginning of a gene on DNA?

  RNA polymerase separates the DNA strands.
• How is an mRNA molecule produced during transcription?

  An mRNA molecule is produced on the template DNA strand using RNA polymerase to link RNA nucleotides.
• What role does complementary base pairing play in transcription?

  RNA polymerase uses complementary base pairing to pair DNA and RNA nucleotides.
• What is the stability of DNA attributed to?

  Strong covalent bonds between the nucleotides.
• What is the significance of somatic cells in relation to DNA stability?

  In somatic cells that do not divide, DNA sequences must be conserved throughout the life of a cell.
• What is gene expression?

  Gene expression is the process by which genetic information in a gene is used to synthesize a functional polypeptide.
• What must occur before mRNA can be translated by a ribosome?

  A gene must be transcribed to mRNA.
• What happens if transcription does not occur?

  If transcription does not occur, then translation cannot occur.
• What is the role of ribosomes in translation?

  Ribosomes synthesize polypeptides using the genetic code of mRNA.
• What is the function of mRNA in translation?

  mRNA brings the genetic code to the ribosome.
• What is the role of tRNA in translation?

  tRNA brings amino acids to the ribosome.
• How do codons on mRNA relate to amino acids?

  Codons are a sequence of three nucleotides that code for an amino acid.
• What ensures the correct sequence of amino acids is synthesized by the ribosome?

  The binding of codons of mRNA and anticodons of tRNA by complementary base pairing.
• What is the genetic code's degeneracy?

  More than one codon may code for the same amino acid.
• What is the universality of the genetic code?

  The same genetic code is used in all life forms.
• How many stop codons are there in the genetic code?

  Three stop codons.
• What is the significance of the start codon in translation?

  The anticodon of the first tRNA binds to a start codon.
• How can the sequence of amino acids in a polypeptide be determined?

  Using the codon sequences in mRNA combined with a table of mRNA codons.
• What is a mutation?

  A mutation is a change to the DNA sequence of an organism.
• What type of mutation causes sickle cell anaemia?

  A single base substitution mutation in the gene for haemoglobin.
• What is the effect of the base substitution mutation in sickle cell anaemia?

  It changes one codon, which changes one amino acid in the alpha-globin molecule.
• What happens to red blood cells in a person with sickle cell disease?

  The red blood cells form a sickle shape and may block small blood vessels.
• What biological processes depend on hydrogen bonding?

  Hydrogen bonding is crucial for processes like transcription and complementary base pairing.