Using the standard genetic code on slide 10 (left table) of week 3 lecture on Proteomics, identify the amino acids X and Y in the provided supplementary figure (Question 1).

Question

BlackTom AI · Accepted Answer

CAU/CAC encode histidine (His), while GUU/GUC/GUA/GUG encode valine (Val). Using the standard genetic code table (mRNA codon → amino acid) is the key to identifying X and Y.

1) Relevant knowledge points and concepts
- Translation reads mRNA in codons (triplets) that map to specific amino acids by the standard genetic code.
- Histidine is encoded by the codons CAU and CAC.
- Valine is encoded by the codons GUU, GUC, GUA and GUG.
- Leucine has distinct codons (UUA, UUG, CUU/CUC/CUA/CUG); aspartic acid is encoded by GAU and GAC.

2) Step-by-step reasoning
- Identify the mRNA codons at the X and Y positions from the supplementary figure (the authoritative answer indicates these codons correspond to His and Val).
- For X: if the triplet is CAU or CAC (first base C, second A, third U or C), lookup in the code table gives histidine.
- For Y: if the triplet is GUA (or any GUx where x = U/C/A/G), lookup gives valine.

3) Intermediate steps / mapping examples
- Example mapping for histidine: mRNA CAU → C (1st) + A (2nd) + U (3rd) → His. Similarly CAC → His.
- Example mapping for valine: mRNA GUA → G (1st) + U (2nd) + A (3rd) → Val. GUU/GUC/GUG similarly map to Val.

4) Why the correct answer is correct
- The standard genetic code directly assigns CAU/CAC to histidine and GUU/GUC/GUA/GUG to valine. If the figure’s X triplet is one of the CA* histidine codons and Y is one of the GU* valine codons, then X = His and Y = Val.

5) Why other options are incorrect
- Option A (His and Leu): Leucine codons are UUA/UUG/CU* and do not match GU* codons for Val.
- Option C (Leu and Asp): Aspartic acid is GAU/GAC, not GU* (Val) or CA* (His).
- Option D (Val and His): reverses the identities; contradicts the codon positions implied by the figure and the provided answer.
- Option E (Asp and Leu): neither Asp nor Leu corresponds to the CA* and GU* codons.

6) Conclusion
Because the codon-to-amino-acid mapping assigns CAU/CAC → His and GUU/GUC/GUA/GUG → Val, the correct identification is X: His (Histidine) and Y: Val (Valine), matching the provided answer.

Using the standard genetic code on slide 10 (left table) of week 3 lecture on Proteomics, identify the amino acids X and Y in the provided supplementary figure (Question 1).Single choice

Similar Questions

Using the genetic code provided below, which polypeptide could be made from the following piece of an mRNA: 5’-...UUAUGCGCAAA...-3’ ? (first three amino acids are indicated in the followings)

The identification of a stop codon for a particular gene is an example of

The reading frame begins with a _ and is read _______.

A tRNA has an anticodon that is 3'-CAU-5'. Which amino acid would it carry?

What is the genetic code?

The order of amino acids in a protein produced by your body is

Question at position 72 True or False. The genetic code in bacteria is different from the genetic code in humans.TrueFalse

Question at position 28 Select all of the attributes of the genetic code.Codons do not overlapEvery codon codes for an amino acidCodons do overlapThe genetic code is not redundantEvery codon is usedThe genetic code is redundant

More Practical Tools for Students Powered by AI Study Helper

Homework AI Solver

Stylized AI Paper Writer

Plagiarism Checker Assistant

Citation AI Academic Writing Tool

In-Class Translation Assistant

AI Note Generator

AI Quiz Answers

Past Exam Questions from University Test Bank

Smart Practice Assistant

Adaptive Practice

Making Your Study Simpler