The parietal cells of the stomach lining contain membrane “pumps” that transport hydrogen ions from the cytosol (pH 7.0) into the stomach, contributing to the acidity of gastric juice (pH 1.0). Calculate the free energy required to transport 1 mol of hydrogen ions through these pumps. (Hint: see Chapter 11.) Assume a temperature of 37 °C.

#Question id: 23570

#Unit 8. Inheritance Biology

#Question id: 1140

#Unit 4. Cell Communication and Cell Signaling

Cell sensitivity to an external signal is determined by:

#Question id: 4267

#Unit 3. Fundamental Processes

The 3D structure of the complete Escherichia coli ribosome with bound mRNA and tRNAs revealed that the very amino terminus of one protein (L27) does reach into the active site. This finding suggested a role for this protein in catalysis. To test this possibility, the nine amino acids at the L27 amino terminus that were in close proximity to the active site were eliminated by mutation. The following possible outcomes were found to be correct as

A. The resulting cells produced ribosomes with reduced but detectable peptidyl transferase activity

B. Region of the L27 protein contributes to peptidyl transferase activity

C. The mutant ribosomes, didn’t synthesised wildtype levels of cells

D. Vast majority of this increase in peptide bond formation is retained, even without the presence of L27 in the active site

E. The most likely role for L27 is to correctly position one or more of the RNA components of the active site

#Question id: 10306

#Unit 6. System Physiology – Plant

pyruvate dehydrogenase (PDH) complex requires five different coenzymes or prosthetic groups and these enzymesalso require four different vitamins in human nutrition are vital components of this system:

#Question id: 30071

#Unit 7. System Physiology – Animal

According to graph, match the following: