text: user15733: I was doing a simple quiz which I encountered the following two questions related to mass spectrum matching with cyclic peptide and linear peptide.
  I have done some preliminary google search, but I am not sure how to use either  https://codereview.stackexchange.com/questions/193859/find-a-cyclic-peptide-with-a-given-non-ideal-spectrum or https://github.com/rochoa85/pepfun in this case.
  
  Which of the following cyclic peptides could have generated the
  theoretical spectrum 0 71 101 113 131 184 202 214 232 285 303 315 345
  416? (Select all that apply.)
  
  TAIM
  
  TMIA
  
  MAIT
  
  MTAI
  
  TMLA
  
  TLAM
  
  
  Which of the following linear peptides is consistent with Spectrum =
  {0 71 99 101 103 128 129 199 200 204 227 230 231 298 303 328 330 332
  333}? (Select all that apply.)
  
  AVQ
  
  TCQ
  
  TVQ
  
  QCV
  
  TCE
  
  ETC
  
  
  user6322: You are way overthinking this.
  As this is homework I won't give any code, but I will throw back some questions:
  
  What is the definition of m/z?
  Were the only tool available Wikipedia, could you simply read the infobox of each residue?
  If so, what values would you need and what elements do you need to subtract?
  Does residue order matter for linear and backbone cyclised peptides? (Let's ignore isoaspartate etc.)
  Have you been introduced to RDKit in your course? E.g. what would this give you?
  
  from rdkit import Chem
  from rdkit.Chem import Descriptors
  mol: Chem.Mol = Chem.MolFromFASTA('ELVIS')
  print( Descriptors.ExactMolWt(mol) )
  
  
original_text: 15733: <p>I was doing a simple quiz which I encountered the following two questions related to mass spectrum matching with cyclic peptide and linear peptide.</p>
  <p>I have done some preliminary google search, but I am not sure how to use either  <a href="https://codereview.stackexchange.com/questions/193859/find-a-cyclic-peptide-with-a-given-non-ideal-spectrum">https://codereview.stackexchange.com/questions/193859/find-a-cyclic-peptide-with-a-given-non-ideal-spectrum</a> or <a href="https://github.com/rochoa85/pepfun" rel="nofollow noreferrer">https://github.com/rochoa85/pepfun</a> in this case.</p>
  <blockquote>
  <p>Which of the following cyclic peptides could have generated the
  theoretical spectrum 0 71 101 113 131 184 202 214 232 285 303 315 345
  416? (Select all that apply.)</p>
  </blockquote>
  <pre><code>TAIM
  
  TMIA
  
  MAIT
  
  MTAI
  
  TMLA
  
  TLAM
  </code></pre>
  <blockquote>
  <p>Which of the following linear peptides is consistent with Spectrum =
  {0 71 99 101 103 128 129 199 200 204 227 230 231 298 303 328 330 332
  333}? (Select all that apply.)</p>
  </blockquote>
  <pre><code>AVQ
  
  TCQ
  
  TVQ
  
  QCV
  
  TCE
  
  ETC
  </code></pre>
   6322: <p>You are way overthinking this.</p>
  <p>As this is homework I won't give any code, but I will throw back some questions:</p>
  <ul>
  <li>What is the definition of m/z?</li>
  <li>Were the only tool available Wikipedia, could you simply read the infobox of each residue?</li>
  <li>If so, what values would you need and what elements do you need to subtract?</li>
  <li>Does residue order matter for linear and backbone cyclised peptides? (Let's ignore isoaspartate etc.)</li>
  <li>Have you been introduced to RDKit in your course? E.g. what would this give you?</li>
  </ul>
  <pre class="lang-py prettyprint-override"><code>from rdkit import Chem
  from rdkit.Chem import Descriptors
  mol: Chem.Mol = Chem.MolFromFASTA('ELVIS')
  print( Descriptors.ExactMolWt(mol) )
  </code></pre>
  