Textbook Question
Contrast the roles of tRNA and mRNA during translation, and list all enzymes that participate in the transcription and translation process.
Ch. 13 - Translation and Proteins
Klug10th EditionEssentials of GeneticsISBN: 9780135588789
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Table of contents
- Ch. 1 - Introduction to Genetics16
- Ch. 2 - Mitosis and Meiosis28
- Ch. 3 - Mendelian Genetics37
- Ch. 4 - Modification of Mendelian Ratios53
- Ch. 5 - Sex Determination and Sex Chromosomes32
- Ch. 6 - Chromosome Mutations: Variation in Number and Arrangement37
- Ch. 7 - Linkage and Chromosome Mapping in Eukaryotes36
- Ch. 8 - Genetic Analysis and Mapping in Bacteria and Bacteriophages24
- Ch. 9 - DNA Structure and Analysis38
- Ch. 10 - DNA Replication29
- Ch. 11 - Chromosome Structure and DNA Sequence Organization22
- Ch. 12 - The Genetic Code and Transcription36
- Ch. 13 - Translation and Proteins27
- Ch. 14 - Gene Mutation, DNA Repair, and Transposition34
- Ch. 15 - Regulation of Gene Expression in Bacteria22
- Ch. 16 - Regulation of Gene Expression in Eukaryotes37
- Ch. 17 - Recombinant DNA Technology27
- Ch. 18 - Genomics, Bioinformatics, and Proteomics30
- Ch. 19 - The Genetics of Cancer21
- Ch. 20 - Quantitative Genetics and Multifactorial Traits37
- Ch. 21 - Population and Evolutionary Genetics45
Chapter 13, Problem 3
List and describe the role of all molecular constituents present in a functional polyribosome.
Verified step by step guidance1
Identify the main molecular constituents of a functional polyribosome, which include mRNA, ribosomes, tRNAs, and various associated proteins.
Describe the role of mRNA as the template that carries the genetic code from DNA to be translated into a polypeptide chain.
Explain that ribosomes are the molecular machines that read the mRNA sequence and catalyze the assembly of amino acids into a polypeptide chain; in a polyribosome, multiple ribosomes simultaneously translate a single mRNA molecule.
Discuss the function of tRNAs as adaptor molecules that bring specific amino acids to the ribosome according to the codon sequence on the mRNA, ensuring correct amino acid incorporation.
Mention additional factors such as initiation, elongation, and release factors that assist in the assembly, progression, and termination of translation within the polyribosome complex.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Polyribosome Structure
A polyribosome, or polysome, is a complex formed when multiple ribosomes simultaneously translate a single mRNA molecule. This arrangement increases the efficiency of protein synthesis by allowing multiple copies of a protein to be produced concurrently from one mRNA strand.
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03:49
Ribosome Structure
Molecular Constituents of Polyribosomes
Key molecular components include mRNA, multiple ribosomes (each composed of large and small subunits), tRNAs carrying amino acids, and various translation factors. These constituents work together to decode the mRNA sequence and synthesize the corresponding polypeptide chains.
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Role of Translation Factors
Translation factors are proteins that assist in initiation, elongation, and termination phases of protein synthesis. They facilitate ribosome assembly on mRNA, ensure correct tRNA positioning, and help release the completed polypeptide, thus ensuring efficient and accurate translation within the polyribosome.
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Related Practice
Textbook Question
On what basis have we concluded that proteins are the end products of genetic expression?
Textbook Question
During translation, what molecule bears the codon? the anticodon?
Textbook Question
Write a short essay that discusses the role of ribosomes in the process of translation as it relates to these concepts.
Textbook Question
How do we know, based on studies of Neurospora nutritional mutations, that one gene specifies one enzyme?
Textbook Question
Francis Crick proposed the 'adaptor hypothesis' for the function of tRNA. Why did he choose that description?