जठर रस (pH 1.5) का उत्पादन रक्त प्लाज्मा (pH 7.4) से H+ को आमाशय (stomach) में पंप करके किया जाता है। 37°C पर एक लीटर जठर रस का उत्पादन करने के लिए H+ परिवहन के लिए आवश्यक मुक्त ऊर्जा की मात्रा की गणना करें। इस ऊर्जा की आपूर्ति के लिए ATP के कितने मोल हाइड्रोलाइज्ड होने चाहिए? (कोशिकीय स्थितियों में ATP हाइड्रोलिसिस के लिए मुक्त ऊर्जा परिवर्तन लगभग -58 kJ/mol है, R = 8.315 J/mol/K)

In a protein stability study, three solutions, MolA (10 kDa) at 0.5 mM, MolB (20 kDa) at 0.5 mM, and MolC (20 kDa) at 1 mM, were subjected to denaturation by urea, SDS, and guanidinium hydrochloride (GnHCl), respectively. The fraction of unfolded protein (f u ) profiles show that f u is 0.2 for MolA at 0.2 M urea, 0.8 for MolB at 0.05% SDS, and 0.9 for MolC at 4.5 M GnHCl. Which one of the following corresponds to reaction conditions at which the absolute number of molecules of folded protein are equal, assuming the reaction volumes to be the same for all experiments?

A 100-residue long protein has a single chromophoric residue (tyrosine). The UV absorption of this protein and a homologous protein (also with a single tyrosine residue) was monitored at 280 nm at different pH conditions. A plot of the absorbance as a function of pH shows a significant difference in their titration curves. Which one of the following rationalizes the difference in the two pH titrations?