Use a net equation for the biosynthesis of tripalmitoylglycerol (tripalmitin) from glycerol and palmitate to show how many ATPs are required per molecule of tripalmitin formed.
C3H5(OH)3 + C15H31COOH → C45H91COO(CH2)29COOH + 3 ATP
The net equation for the biosynthesis of tripalmitin from glycerol and palmitate can be represented as follows:
3 Palmitate + Glycerol → Tripalmitin + 3 Water
To determine the number of ATPs required per molecule of tripalmitin formed, we need to consider the ATP equivalents required for the biosynthesis.
During the synthesis of tripalmitin, two ATP equivalents are required for converting each palmitate into palmitoyl-CoA. This conversion occurs through a series of reactions known as β-oxidation.
Therefore, since tripalmitin consists of three palmitate molecules, a total of 3 x 2 = 6 ATP equivalents are required for the activation of palmitate.
Additionally, the synthesis of tripalmitin requires the esterification of palmitoyl-CoA with glycerol. This process involves the transfer of a fatty acid group from palmitoyl-CoA to glycerol, forming a triglyceride molecule. Esterification reactions generally do not consume ATP directly.
Hence, the net equation for the biosynthesis of tripalmitin does not involve direct ATP consumption. The only step requiring ATP equivalents is the activation of palmitate to palmitoyl-CoA.
Thus, for the production of one molecule of tripalmitin, 6 ATP equivalents are required.