Biology I / What Is Life? The Chemistry of Living Things
Practice question · Numerical answer

A protein chain is assembled from 150 amino acids joined into one continuous strand. How many water molecules are released in forming it?

Hints
  1. Each peptide bond formed releases exactly one water molecule.
  2. Joining n monomers into one chain forms n - 1 bonds.
Show the answer

149

Why

Joining 150 amino acids into a single chain forms 1501=149150 - 1 = 149 peptide bonds, and condensation releases one water per bond, so 149 water molecules. The off-by-one is the point: bonds count the gaps, not the units.

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