Protein synthesis

• What should you be able to describe by the end of the video?

  The stages of protein synthesis
• Why is this topic considered tricky for exams?

  It involves a lot of detail
• What is DNA made of?

  Double-stranded polymer of nucleotides
• How many different nucleotides are there?

  Four different nucleotides
• What are the bases of nucleotides called?

  A, T, G, and C
• How do the two strands of DNA relate to each other?

  They are complementary
• Which base pairs with adenine (A)?

  Thymine (T)
• Which base pairs with cytosine (C)?

  Guanine (G)
• What are proteins made of?

  Polymers of amino acids
• How many different amino acids are there in humans?

  Twenty different amino acids
• What determines the shape of a protein?

  The specific order of amino acids
• What is an example of an enzyme molecule?

  Amylase
• What is an example of a structural protein?

  Collagen
• What is an example of a hormone?

  Insulin
• How is the order of amino acids in a protein determined?

  By the sequence of bases in the gene
• What happens when a cell makes a protein?

  The cell reads the DNA sequence
• What is the first stage of protein synthesis called?

  Transcription
• Where does transcription take place?

  In the nucleus
• What is the complementary template molecule called?

  Messenger RNA (mRNA)
• What is the structure of mRNA?

  It is a single-stranded molecule
• What is the second stage of protein synthesis called?

  Translation
• Where does translation take place?

  In the cytoplasm
• What attaches to the ribosome during translation?

  The mRNA molecule
• What are the carrier molecules that bring amino acids to the ribosome called?

  Transfer RNA (tRNA)
• What does the ribosome do during translation?

  Reads the triplets of bases on mRNA
• What is formed when the protein chain is complete?

  It folds into its unique shape
• Why is the shape of a protein important?

  It enables the protein to do its job
• What are the stages of protein synthesis?

  1. Transcription

  • Takes place in the nucleus
  • DNA sequence is copied to mRNA

  1. Translation

  • Takes place in the cytoplasm
  • mRNA attaches to ribosome
  • tRNA brings amino acids
  • Ribosome reads mRNA triplets
  • Amino acids are joined in order
  • Protein folds into shape
• What are the roles of different proteins?

  • Enzymes (e.g., amylase)
  • Structural proteins (e.g., collagen)
  • Hormones (e.g., insulin)
• What is the relationship between DNA, genes, and proteins?

  • DNA contains genes
  • Genes determine amino acid sequences
  • Amino acid sequences form proteins