tRNA Structure and Function
29 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the approximate length of a transfer RNA (tRNA) molecule?

  • 50 nucleotides
  • 120 nucleotides
  • 100 nucleotides
  • 80 nucleotides (correct)

    • What is the function of the short single-stranded region at the 3ʹ end of a tRNA molecule?

  • Recognizing codons in mRNA
  • Attaching amino acids to tRNA (correct)
  • Binding to ribosomes
  • Pairing with other tRNA molecules

    • How many different types of synthetase enzymes are typically present in most cells?

  • 10
  • 40
  • 20 (correct)
  • 60

    • What is the reason why there are not 64 different types of tRNA?

    <p>Some tRNA can recognize more than one codon</p> Signup and view all the answers

    What type of base pairing occurs in the wobble position of the anticodon?

    <p>Non-canonical base pairing</p> Signup and view all the answers

    What is the function of aminoacyl-tRNA synthetases?

    <p>To couple each amino acid to its appropriate tRNA molecule</p> Signup and view all the answers

    What is the primary function of the A site and the P site in a ribosome?

    <p>To form base pairs with adjacent codons on the mRNA molecule</p> Signup and view all the answers

    What is the consequence of tRNA binding to the ribosomal A site?

    <p>The P site and the A site contain adjacent bound tRNAs</p> Signup and view all the answers

    What is the significance of the 'wobble' in the anticodon of the tRNA molecule?

    <p>It allows for specific binding of tRNA to the mRNA molecule, despite variations in the codon</p> Signup and view all the answers

    What is the outcome of protein synthesis initiation?

    <p>Each new amino acid is added to the elongating chain in a cycle of reactions</p> Signup and view all the answers

    What is the role of the E site in a ribosome?

    <p>It is not mentioned in the text as a specific site</p> Signup and view all the answers

    What is the outcome of the tRNA binding to the ribosomal A site in step 1 of protein synthesis?

    <p>The P site and the A site contain adjacent bound tRNAs</p> Signup and view all the answers

    What is the role of initiation factors in protein synthesis?

    <p>They recognize the initiator tRNA–methionine complex</p> Signup and view all the answers

    What would be the consequence of an error of one nucleotide in the starting site of protein synthesis?

    <p>The reading frame would be shifted, resulting in a nonfunctional protein</p> Signup and view all the answers

    What is the function of the initiator tRNA in protein synthesis?

    <p>It carries the amino acid methionine and starts translation</p> Signup and view all the answers

    What is the role of the sequence AUG in protein synthesis?

    <p>It signals the start of protein synthesis</p> Signup and view all the answers

    What is unique about the initiator tRNA compared to other tRNAs carrying methionine?

    <p>It has a different nucleotide sequence</p> Signup and view all the answers

    Where does the initiator tRNA–methionine complex get loaded in eukaryotes?

    <p>The small ribosomal subunit</p> Signup and view all the answers

    What is the advantage of multiple initiations of protein synthesis in eukaryotes?

    <p>It enables the cell to produce more protein molecules in a given time</p> Signup and view all the answers

    What is the significance of the 5ʹ and 3ʹ ends of mRNA in eukaryotes?

    <p>They interact, allowing for rapid reinitiation of translation</p> Signup and view all the answers

    Why are certain antibiotics effective against bacteria but not eukaryotes?

    <p>Because they exploit structural and functional differences between bacterial and eukaryotic ribosomes</p> Signup and view all the answers

    What is the implication of the multiple steps from DNA to protein?

    <p>It provides multiple opportunities for regulation of gene expression</p> Signup and view all the answers

    What is the advantage of using inhibitors of prokaryotic protein synthesis as antibiotics?

    <p>They can be taken in high dosages without undue toxicity to humans</p> Signup and view all the answers

    What is the function of release factors in protein synthesis?

    <p>To bind to a ribosome with a stop codon to catalyze the addition of a water molecule</p> Signup and view all the answers

    What happens to the growing polypeptide chain after the addition of a water molecule?

    <p>It is released into the cytoplasm</p> Signup and view all the answers

    What is the purpose of multiple initiations on an mRNA molecule?

    <p>To increase the rate of protein synthesis</p> Signup and view all the answers

    What is the term for a large cytoplasmic assembly made up of several ribosomes spaced along a single mRNA molecule?

    <p>Polyribosome</p> Signup and view all the answers

    What happens to the ribosome after the release of the completed protein chain?

    <p>It is recycled for another round of protein synthesis</p> Signup and view all the answers

    What is the typical time range for the synthesis of a protein molecule?

    <p>20 seconds to several minutes</p> Signup and view all the answers

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser