<p>I know the Princeton Review 2013 AP Biology was complete crap, but only because of the organization and information covered. However, I am starting to notice POSSIBLE informational errors. </p>
<p>My question: Which serves as the template for RNA polymerase: the sense strand or antisense strand on DNA? That is, which is complementary to the mRNA?</p>
<p>Quote from PR 2013 AP Biology pg. 85
"Because RNA is single stranded, we have to copy only one of the two DNA strands. The strand that serves as the template is the sense strand. The other strand that lies dormant is the antisense strand." </p>
<p>However, Wikipedia and Bozeman Biology (Youtube channel) states otherwise. </p>
<p>From Wikipedia:
"The sense strand is the strand of DNA that has the same sequence as the mRNA, which takes the antisense strand as its template during transcription, and eventually undergoes (typically, not always) translation into a protein."</p>
<p>May someone please clear up this issue?</p>
<p>EDIT: Another short question. Are amino acids carried by tRNA based on the sequence found in the mRNA's codon or the tRNA's anticodon?</p>
<p>For example, AUG is the starting amino acid methionine. Is it AUG on the mRNA or AUG on the tRNA (thus UAC on the mRNA). If it's AUG on the mRNA, what's the use of anticodons on tRNA?</p>
<p>I have no idea what sense and anti-sense strands are, lol. Since that’s from the AP book, I doubt that will be on the subject test. But, I do know the answer to the other question. Since the tRNA “picks up” the amino acids in the cell and takes them to the ribosome, and the mRNA is responsible for carrying the protein’s information from the DNA to the ribosome, that must mean tRNA has AUG (methionine). Furthermore, the amino acids the tRNA picks up are dictated by the mRNA’s codon’s, so therefore you know that the mRNA has UAC (opposite of AUG). </p>
<p>TL;DR version:<br>
mRNA - dictates the sequence of amino acids since it has the information for the protein.
tRNA - gets the amino acids and therefore carries AUG (methionne).</p>
<p>The template strand is antisense and is the strand that is copied. The nontemplate strand is the sense strand (also called coding strand) and is not copied and is the strand with the same base sequence as the RNA transcribed (with the exception of the uracils, of course). At least this is according to my professor’s powerpoint slides (my molecular biology textbook just calls them “template” or “nontemplate” and doesn’t mention anything about sense. Same with Campbell Biology 9th edition).</p>
<p>Codons, such as AUG, are on mRNA. So the anticodon on the tRNA is complementary to this.
It’s something like this:</p>
<p>3’UAC5’
5’AUG3’</p>
<p>The bottom is the codon on the mRNA and the top is the anticodon on the tRNA. The codons on codon tables refer to sequences on mRNA. Interesting fact - tRNAs are not limited to A, U, G, or C. They have have I (inosine) as well. So you would see Is as well in addition to the other nucleotides on a codon table if it actually referred to the anticodon.</p>
<p>I’m not sure what you’re asking though. Each tRNA is bound to a specific amino acid. The anticodon is there so that the correct tRNA will bind to the codon, and consequently the correct amino acid will be attached to the growing polypeptide.</p>
<p>Oops, yeah I got the part about AUG wrong. Methionine is THE COMPLIMENT of AUG (UAC).</p>
<p>@aldfig0:
Good job in explanation. I would just skip the inosine part though. Codon table usually do not show the inosine on it. In addition, there are 3 stop codons, so not all tRNA carry an amino acid residue.</p>
<p>Oh I understand. So the tRNA’s anticodon does not exactly affect the amino acid picked up; it’s just to match with the mRNA’s codon.</p>
<p>And I’m assuming Princeton Review messed up in it’s information on sense/anti-sense strands now. Thanks!</p>
<p>^ In a way, it does. The amino acid residue carried by the tRNA is specific to the anticodon it has. That is the way to guarantee error free translation. There are, however, mutations that can change that.
Princeton Review is usually good. McGraw Hills is common to make mistakes. Good that you realize something does not make sense on sense/antisense in a sense on the book. :)</p>