SOLUTION: An octapeptide is known to contain four of one amino acid, two of another, two of third.How many different amino acids sequence are pissible

Algebra.Com
Question 1092600: An octapeptide is known to contain four of one amino acid, two of another, two of third.How many different amino acids sequence are pissible
Found 2 solutions by addingup, ikleyn:
Answer by addingup(3677)   (Show Source): You can put this solution on YOUR website!
Does order matter? Is there a specific way they have to be combine? If you have to watch the order of the arrangement... you don't have enough information.
IF order doesn't matter, then:
4+2+2 = 8
8*7*6*5*4*3*2 = 8! = number of combinations
Answer by ikleyn(52818)   (Show Source): You can put this solution on YOUR website!
.
Hey, I answered to similar post before.

But you sent it again, and it is  VERY GOOD,  because I changed my mind comparing with my earlier posts.

I made my small research in the Internet regarding  "octapeptide".

What I learned in relation to our problem is  THIS: 

1.  Octapeptide is an line chain of 8 amino acids.


2.  These elementary amino acids may repeat in the chain. Repeating is allowed.


3.  For our problem it does not matter that there are 4 amino acids of one type, 

    2 amino acids of the other type and  2 amino acids of the third type.


4.  I still didn't find if there are restrictions for the order of placing amino acids in the line.

    I suspect that a compehensive answer to this last question is in dark for chemists/biochemists.





    I will ASSUME that the problem asks in how many ways 8 different amino acids can be placed in a row if repeating is allowed.


    Then the answer is:  in   = 16777216 ways.


    Any of 8 in the first position.
    Any of 8 in the second position.
    Any of 8 in the third position.
    ........  and  so  on  .......
    Any of 8 in the eighth position.


In all,  = 16777216 ways.




RELATED QUESTIONS

An octapeptide is known to contain four of one amino acid, two of another and two of... (answered by Fombitz,ikleyn,greenestamps)
``An octapeptide is known to contain four of one amino acid, two of another and two of... (answered by ikleyn)
In how many ways can four different amino acids be arranged into a polypeptide chain of... (answered by ikleyn,greenestamps)
In how many ways can 20 different amino acids be arranged into a polypeptide chain of 5... (answered by ewatrrr)
20 different amino acids are essential to life To study the folding of proteins caused... (answered by ikleyn)
In how many ways can 12 different amino acids be arranged into a polypeptide chain of... (answered by ikleyn)
Question 1 [7 marks] a) A coin is tossed three times, calculate the probability that... (answered by greenestamps)
In the chemistry lab, a certain acid is stored in two different dilutions. One bottle... (answered by stanbon)
A chemist has two prepared acid solutions, one of which is 2% acid by volume,... (answered by josgarithmetic)