أسئلة الجينتكس السابعة (قبل التعديل)
50 Questions
0 Views

أسئلة الجينتكس السابعة (قبل التعديل)

Created by
@inspireeAcademy

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

How many sense codons code for amino acids?

  • 3
  • 64
  • 61 (correct)
  • 20

    • Which of the following is a termination codon?

  • AUC
  • AUG
  • UAA (correct)
  • CUG

    • What role does AUG serve in the process of translation?

  • It has no function.
  • It initiates protein synthesis. (correct)
  • It encodes for a termination signal.
  • It encodes for an amino acid other than methionine.

    • How many non-sense codons are there in the genetic code?

    <p>3</p> Signup and view all the answers

    If there are 64 total codons, what is the maximum number of unique amino acids that can be coded for?

    <p>20</p> Signup and view all the answers

    What term describes an amino acid that is attached to its specific tRNA?

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

    What type of bond forms between an amino acid and its specific tRNA during activation?

    <p>Ester bond</p> Signup and view all the answers

    Which type of enzyme is specifically involved in the synthesis of proteins by catalyzing the attachment of amino acids to their respective tRNA?

    <p>Synthetase enzyme</p> Signup and view all the answers

    What is the first step required before an amino acid can participate in protein synthesis?

    <p>Activation of amino acids</p> Signup and view all the answers

    What is the main source of energy required for the process of protein synthesis?

    <p>ATP and GTP</p> Signup and view all the answers

    Which of the following statements is true regarding tRNA?

    <p>tRNA carries activated amino acids only.</p> Signup and view all the answers

    During the activation of amino acids, what is primarily being synthesized?

    <p>Aminoacyl-tRNA</p> Signup and view all the answers

    Which factor is primarily responsible for promoting the elongation phase of protein synthesis?

    <p>Elongation factors</p> Signup and view all the answers

    What role do releasing factors play in the process of protein synthesis?

    <p>Terminate the protein synthesis</p> Signup and view all the answers

    Which of the following is NOT a type of protein factor involved in protein synthesis?

    <p>Translocation factors</p> Signup and view all the answers

    What causes the termination of polypeptide chain elongation during translation?

    <p>Encountering a non-sense codon</p> Signup and view all the answers

    Which of the following codons are classified as non-sense codons?

    <p>UAA, UAG, UGA</p> Signup and view all the answers

    What happens to the A site of the ribosome when a non-sense codon is presented during translation?

    <p>It becomes free for other tRNAs to bind.</p> Signup and view all the answers

    Which statement correctly describes the role of non-sense codons in the translation process?

    <p>They act as stop signals for translation.</p> Signup and view all the answers

    During translation, what occurs immediately after encountering a non-sense codon?

    <p>Termination factors are recruited to facilitate release.</p> Signup and view all the answers

    How many high energy phosphate bonds are cleaved for the formation of one peptide bond?

    <p>4</p> Signup and view all the answers

    Which two types of energy sources are primarily used in the formation of a peptide bond?

    <p>ATP and GTP</p> Signup and view all the answers

    What role does GTP play in the process of peptide bond formation?

    <p>It assists in the binding of aminoacyl-tRNA and translocation.</p> Signup and view all the answers

    How many ATP molecules are directly involved in the activation of amino acids for peptide bond formation?

    <p>1</p> Signup and view all the answers

    What is the total number of GTP molecules cleaved during the formation of one peptide bond?

    <p>1</p> Signup and view all the answers

    What is the primary function of mRNA in the process of protein synthesis?

    <p>To carry the genetic instructions from DNA to the ribosome</p> Signup and view all the answers

    Which component is primarily responsible for linking amino acids to their corresponding tRNA?

    <p>Aminoacyl-tRNA</p> Signup and view all the answers

    How are amino acids classified in the context of protein synthesis?

    <p>They are the building blocks of proteins</p> Signup and view all the answers

    What is the role of tRNA in protein synthesis?

    <p>To transfer amino acids to the ribosome</p> Signup and view all the answers

    In the protein synthesis process, what do the amino acids bind to before being incorporated into a protein?

    <p>Aminoacyl-tRNA</p> Signup and view all the answers

    How many high energy phosphate bonds are cleaved in total when forming one peptide bond?

    <p>4</p> Signup and view all the answers

    Which energy source is NOT utilized during the formation of one peptide bond?

    <p>2 ATP</p> Signup and view all the answers

    What is the total number of GTP molecules cleaved specifically for the binding and translocation during peptide bond formation?

    <p>2</p> Signup and view all the answers

    Which process involves the cleavage of high energy bonds for peptide bond formation?

    <p>Activation of amino acids</p> Signup and view all the answers

    For the activation of amino acids in peptide bond formation, which of the following statements is true?

    <p>It cleaves 2 high energy phosphate bonds from 1 ATP.</p> Signup and view all the answers

    What is formed when prokaryotic 50S and 30S ribosomal subunits combine?

    <p>70S ribosome</p> Signup and view all the answers

    Which statement is true regarding the ribosomal subunits involved in prokaryotic translation?

    <p>The 50S and 30S subunits combine to form a 70S ribosome.</p> Signup and view all the answers

    Which component of the ribosome is responsible for catalyzing peptide bond formation?

    <p>peptidyl transferase enzyme</p> Signup and view all the answers

    What is the primary movement of the ribosome after the formation of a peptide bond?

    <p>It moves 3 nucleotides towards the 3' end of mRNA.</p> Signup and view all the answers

    What distinguishes the 70S ribosome from the 80S ribosome?

    <p>The 70S ribosome is smaller than the 80S ribosome.</p> Signup and view all the answers

    Which ribosomal subunit contains the peptidyl transferase enzyme responsible for peptide bond formation?

    <p>60S subunit</p> Signup and view all the answers

    Which of the following is a characteristic of prokaryotic ribosomes?

    <p>They consist of 50S and 30S subunits.</p> Signup and view all the answers

    How do prokaryotic ribosomes facilitate protein synthesis?

    <p>By forming the 70S ribosome from 50S and 30S subunits.</p> Signup and view all the answers

    What process follows peptide bond formation during translation?

    <p>Translocation of the ribosome</p> Signup and view all the answers

    Which of the following statements about ribosomal movement during translation is accurate?

    <p>The ribosome moves 3 nucleotides towards the 3' end of mRNA post peptide bond formation.</p> Signup and view all the answers

    What is the primary advantage of forming a polyribosome during translation?

    <p>It facilitates the production of multiple polypeptides from a single mRNA strand.</p> Signup and view all the answers

    How do polysomes affect the efficiency of protein synthesis?

    <p>They contribute to faster production of proteins by utilizing multiple ribosomes.</p> Signup and view all the answers

    What is the structural feature of polysomes?

    <p>Multiple ribosomes translating a single mRNA.</p> Signup and view all the answers

    What is produced as a result of a polyribosome translating a single mRNA?

    <p>Multiple distinct polypeptides varying in length and composition.</p> Signup and view all the answers

    Which statement accurately describes the relationship between mRNA and polyribosomes?

    <p>Polyribosomes can translate mRNA into several different polypeptides simultaneously.</p> Signup and view all the answers

    Study Notes

    Codons

    • There are 64 codons.
    • 61 codons code for 20 amino acids.
    • 3 codons are non-sense codons or termination codons (UAA, UAG, UGA).

    Initiation Codon

    • AUG codes for methionine and acts as the initiation codon for translation.

    Translation Process

    • Translation requires initiation, elongation and termination steps.
    • Initiation: Involves initiation factors (IF).
    • Elongation: Involves elongation factors (EF).
    • Termination: Involves releasing factors (RF).
    • Energy Sources: ATP & GTP.

    Activation of Amino Acids

    • Amino acids must be activated before translation.
    • Amino acids bind to specific tRNA molecules via an ester bond.
    • This process is called aminoacyl-tRNA synthesis.

    Termination

    • Elongation continues until the A site is occupied by a non-sense codon (UAA, UAG, UGA).
    • This signals the termination of translation.

    Energy Needs

    • Four high energy phosphate bonds are cleaved for each new peptide bond formed:
      • 2 ATP: Used for activation of amino acids.
      • 1 GTP: Used for binding aminoacyl-tRNA to the A site.
      • 1 GTP: Used for translocation.

    Translation Overview

    • mRNA carries genetic information from DNA to the ribosome.
    • tRNA carries amino acids to the ribosome.
    • Amino acids are the building blocks of proteins.
    • Aminoacyl-tRNA synthetase connects specific amino acids to their corresponding tRNA molecules.

    Ribosome Formation and Function

    • Prokaryotic ribosomes are composed of a 30S and a 50S subunit, which assemble to form a 70S ribosome.
    • The formation of a peptide bond is catalyzed by peptidyl transferase, an enzyme located within the 60S subunit.
    • Following the formation of a peptide bond, the ribosome moves three nucleotides along the mRNA towards the 3' end.

    Energy Requirements

    • Four high-energy phosphate bonds are cleaved for each new peptide bond formed:
      • Two ATP molecules are required for amino acid activation.
      • One GTP molecule is used for the binding of aminoacyl-tRNA to the A site.
      • One GTP molecule is used for translocation.

    Polyribosomes

    • Multiple ribosomes can translate a single mRNA molecule simultaneously, forming a polyribosome (or polysome).
    • This process allows for the production of many polypeptides from a single mRNA molecule, increasing protein synthesis efficiency.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Genetics Lecture 7 PDF

    More Like This

    Translation Process
    5 questions

    Translation Process

    IndustriousEcstasy avatar
    IndustriousEcstasy
    Traduction Acides aminés et codons
    22 questions

    Traduction Acides aminés et codons

    Chevrus avatar
    Chevrus
    mRNA Translation Process Quiz
    18 questions

    mRNA Translation Process Quiz

    CompactAnaphora avatar
    CompactAnaphora
    Biology Translation Flashcards
    17 questions

    Biology Translation Flashcards

    PatientYttrium avatar
    PatientYttrium
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser