Protein Synthesis

Click on the links below to find the answer to each of these questions.

  1. State three differences between DNA and RNA. [answer]
  2. If a coding strand of DNA is 18- nucleotides, how many amino acids will be in the polypeptide that is formed? [answer] How many nucleotides will be in the mRNA? [answer] How many anticodons will there be? [answer]
  3. Describe the function of tRNA. [answer]

Use the m-RNA codes and the sequence of the polypeptide shown below to answer the next two questions. Remember, the codes below are mRNA codes, not DNA codes. 

AAG - lysine GAA - glutamic acid
ACU - threonine    GGC - glycine
AGU - serine GUA - valine
CAU - histidine UAA - tyrosine
CCG - proline UGA - tryptophan
CUU - leucine UUC - phenylalanine

polypeptide:   proline-tyrosine-histidine-valine-glutamic acid

  1. What is the base sequence of the mRNA that codes for the polypeptide listed above? [help with the answer]
  2. What is the base sequence of the coding strand of DNA that was necessary for the production of the polypeptide? [help with the answer]
  3. What is the difference between primary mRNA and mature mRNA? [answer]
  4. What word refers to a part of mRNA that must be removed before mature mRNA is produced? [answer]
  5. What is the function of mRNA? [answer]
  6. What is the function of ribosomal RNA? [answer]
  7. What is a codon? [answer]
  8. What is transcription? [answer]  Describe the process. [answer]
  9. Define translation. Describe the process. [answer
  10. What is meant by the term "genetic code"? [answer]
  11. What is a point mutation? [answer]
  12. What is a frameshift mutation? [answer]
  13. Which of the two mutation types (point or frameshift) are the most serious? Why? [answer]
 
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