A DNA sequence encoding a five-amino acid polypeptide is...

Question

A DNA sequence encoding a five-amino acid polypeptide is given below.
...ACGGCAAGATCCCACCCTAATCAGACCGTACCATTCACCTCCT...
...TGCCGTTCTAGGGTGGGATTAGTCTGGCATGGTAAGTGGAGGA...

Give the polypeptide sequence, and identify the N terminus and C terminus.

Accepted Answer

Hi, everyone. Welcome back. Here's our next question. A codon is a set of three letter combinations of bases like code for a particular amino acid, which of the following codons codes for peptide chain termination choice A A G C C G A U A G choice B U A G U G C U A A to C U A A U A G U G A or choice D, all of the above. So we recall that while most codons code for particular amino acid, some codons are non coding and are known as stop codons because they signal the end of the polypeptide chain and the end of translation. And there are three stop codons. So we know that the answer cannot be choice D all of the above because our three choices each have three coons and that would give us more than three stop codons. So let's think about what our three stop codons are. And there's a fun and easy way to remember the stop codons, think of someone that's annoying. You want them to stop bothering you and that can help you remember that we've got U A A for you are annoying U G A, you go away M U A G U R gone. So with that in mind are three annoying stop codons. One thing to note, they all have to start with the letter U. So that also lets you eliminate choice A which has a code on beginning with a and then let's look carefully at B N C, both of which have three codons all beginning with the letter U and looking at B we see U A G which is one of our codons. So that's correct. But then we have U G C which is not one of our codons. So we can eliminate choice B so let's double check. Choice C U A A yes, U A G yes and U G A. So choice C is going to be our answer. Which of the following codones codes for peptide chain termination choice C U A A U A G U G A. See you in the next video.

A DNA sequence encoding a five-amino acid polypeptide is given below.
...ACGGCAAGATCCCACCCTAATCAGACCGTACCATTCACCTCCT...
...TGCCGTTCTAGGGTGGGATTAGTCTGGCATGGTAAGTGGAGGA...

Give the polypeptide sequence, and identify the N terminus and C terminus.

Key Concepts

DNA and RNA Transcription

Translation and Amino Acids

Polypeptide Structure: N Terminus and C Terminus

Watch next

A DNA sequence encoding a five-amino acid polypeptide is given below....ACGGCAAGATCCCACCCTAATCAGACCGTACCATTCACCTCCT......TGCCGTTCTAGGGTGGGATTAGTCTGGCATGGTAAGTGGAGGA...Give the polypeptide sequence, and identify the N terminus and C terminus.

Key Concepts

DNA and RNA Transcription

Translation and Amino Acids

Polypeptide Structure: N Terminus and C Terminus

Watch next

A DNA sequence encoding a five-amino acid polypeptide is given below.
...ACGGCAAGATCCCACCCTAATCAGACCGTACCATTCACCTCCT...
...TGCCGTTCTAGGGTGGGATTAGTCTGGCATGGTAAGTGGAGGA...

Give the polypeptide sequence, and identify the N terminus and C terminus.