Table of contents

1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

26. Nucleic Acids and Protein Synthesis

Introduction to Translation

GOB Chemistry

26. Nucleic Acids and Protein Synthesis

Introduction to Translation

Previous problemNext problem

0:51 minutes

Problem 48

Textbook Question

Why are there at least 20 different tRNAs?

Verified step by step guidance

Understand the role of tRNA: Transfer RNA (tRNA) is responsible for bringing the correct amino acid to the ribosome during protein synthesis. Each tRNA has an anticodon that pairs with a specific codon on the mRNA strand.

Recall the genetic code: The genetic code consists of 64 codons (triplets of nucleotides) that correspond to 20 standard amino acids. Some amino acids are encoded by more than one codon, a phenomenon known as codon redundancy or degeneracy.

Recognize the specificity of tRNA: Each tRNA molecule is specific to one amino acid and has an anticodon that matches the codon for that amino acid. This ensures accurate translation of the genetic code into a protein sequence.

Explain the need for at least 20 tRNAs: Since there are 20 standard amino acids, there must be at least 20 different tRNAs to ensure that each amino acid is properly matched to its corresponding codon during translation.

Consider wobble pairing: Some tRNAs can recognize multiple codons due to wobble base pairing at the third position of the codon. This reduces the total number of tRNAs needed, but there must still be at least 20 to account for all amino acids.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

51s

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

tRNA Structure and Function

Transfer RNA (tRNA) is a type of RNA molecule that plays a crucial role in translating the genetic code into proteins. Each tRNA molecule has a specific structure that includes an anticodon region, which pairs with a corresponding codon on mRNA, and an amino acid attachment site. This structure allows tRNA to deliver the correct amino acid to the growing polypeptide chain during protein synthesis.

Genetic Code and Codons

The genetic code consists of sequences of nucleotides in mRNA that are read in groups of three, known as codons. Each codon specifies a particular amino acid or a stop signal during protein synthesis. Since there are 64 possible codons (4 nucleotides raised to the power of 3), but only 20 standard amino acids, multiple codons can correspond to the same amino acid, necessitating a diverse set of tRNAs to ensure accurate translation.

Wobble Hypothesis

The wobble hypothesis explains how some tRNAs can recognize more than one codon due to flexibility in base pairing at the third position of the codon. This allows for a reduced number of tRNA molecules while still accommodating the 64 codons. However, to maintain fidelity in protein synthesis and to account for all codons, at least 20 distinct tRNAs are required, each specific to one or more amino acids.

Watch next

Master Introduction to Translation Concept 1 with a bite sized video explanation from Jules

Start learning