If three glycine molecules (relative molecular mass 75) react together to form a tripeptide, the relative molecular mass of the product would be
A - VCE - SSCE Chemistry - Question 17 - 2003 - Paper 1
Question 17
If three glycine molecules (relative molecular mass 75) react together to form a tripeptide, the relative molecular mass of the product would be
A. 171
B. 189
C. 20... show full transcript
Worked Solution & Example Answer:If three glycine molecules (relative molecular mass 75) react together to form a tripeptide, the relative molecular mass of the product would be
A - VCE - SSCE Chemistry - Question 17 - 2003 - Paper 1
Step 1
Calculate the total mass of glycine molecules
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Answer
The relative molecular mass of one glycine molecule is 75. For three glycine molecules, the total mass is:
3imes75=225
Step 2
Account for the water molecule loss during condensation reaction
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Answer
When three glycine molecules react to form a tripeptide, two water molecules are lost (one for each bond formed). The mass of water is 18 (molecular mass of H₂O). Therefore, the total mass that will be subtracted is:
2imes18=36
Step 3
Determine the relative molecular mass of the tripeptide
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Answer
Now, we subtract the mass of the water from the total mass of glycine:
225−36=189
Thus, the relative molecular mass of the tripeptide is 189.
