Question

To appreciate the magnitude of the cellular energy expenditure associated with translation, calculate the minimum number of nucleotide triphosphate molecules that are hydrolyzed in the synthesis of a 200-amino-acid bacterial protein. Fill in your answers as numbers below (i.e., 2, 20, 200, 300, etc.) in the prompts below. . For each amino acid, ATP is hydrolyzed during activation for tRNA charging. GTP is hydrolyzed per initiation event by IF-2. GTP is hydrolyzed during EF-Tu mediated binding of tRNAs to the A site, and GTP is hydrolyzed by EF-G during translocation. GTP is hydrolyzed per termination event by RF-3. GTP is hydrolyzed per ribosome recycling event by EF-G. An additional ATP may be consumed each time an incorrectly activated amino acid is hydrolyzed by the deacylation activity of an aminoacyl-tRNA synthetase, as part of its proofreading activity, but do not include that potential proof-reading energy expenditure in the calculation of your total, since the question is asking you to calculate the minimum number of required nucleotide triphosphates. In total, the minimum number of nucleotide triphosphates required to synthesize a 200-amino acid bacterial protein is

Answer 1

1 ATP is hydrolysed for each aminoacid during amino acylaton of tRNA

1 GTP is hydrolysed per initiation event by IF-2

200 GTPs are hydrolysed during the EF-TU mediated binding of tRNAs to the A-site

200 GTPs are hydrolysed by EF-G during translocation

1 GTP is hydrolysed per termination event by RF-3

1 GTP is hydrolysed per ribosome recycling event by EF-G

An additional 1 ATP may be consumed each time an incorrectly activated amino acid is hydrolysed by synthetase as part of its proof-reading activty.

In total the minimum number of NTPs required to synthesize a 200 amino acid bacterial protein is 603