I got a homework question that asks the following.
"How many different tripeptides can be formed from one molecule each of the amino acids tyrosine, valine, and alanine?"
However, I'm not quite sure I understand what its asking.
I thought "maybe its asking how many peptide bonds are needed to bond the three amino in which case the answer would be 2." However, these are tripeptides we are talking about and it only gives 3,6,9,12,24 as answer choices. So If I were to pick 3 that would mean I have 9 peptide bonds throughout the whole protein chain???? Please help this confused chemistry student!
Notice: Please do not use my question to advertise something for sell or cheat by saying "I don't know" or "google it" or anything to that matter. I report cheaters.
"How many different tripeptides can be formed from one molecule each of the amino acids tyrosine, valine, and alanine?"
However, I'm not quite sure I understand what its asking.
I thought "maybe its asking how many peptide bonds are needed to bond the three amino in which case the answer would be 2." However, these are tripeptides we are talking about and it only gives 3,6,9,12,24 as answer choices. So If I were to pick 3 that would mean I have 9 peptide bonds throughout the whole protein chain???? Please help this confused chemistry student!
Notice: Please do not use my question to advertise something for sell or cheat by saying "I don't know" or "google it" or anything to that matter. I report cheaters.
-
When it is asking about different tripeptides, it is essentially referring to the order of amino acids in the tripeptide. This will be equal to 3! (i.e. 3 factorial or 3 x 2 x 1 = 6). Thus you can make six different tripeptides using the three amino acids. Since the no. is manageable, let us see if we can do this the old fashioned way
Tyr-val-ala
Tyr-ala-val
Val-tyr-ala
val-ala-tyr
ala-tyr-val
ala-val-tyr
There you have it. If instead you have one more amino acid, then the combinations will be equal to 4! or 4*3*2*1 = 24. Now imagine with the 20 different amino acids, how many combos you can get. That is why proteins are so diverse and fascinating
Tyr-val-ala
Tyr-ala-val
Val-tyr-ala
val-ala-tyr
ala-tyr-val
ala-val-tyr
There you have it. If instead you have one more amino acid, then the combinations will be equal to 4! or 4*3*2*1 = 24. Now imagine with the 20 different amino acids, how many combos you can get. That is why proteins are so diverse and fascinating