question archive Question 1) Why is cooperative binding of oxygen by hemoglobin essential to its function? Please give a concise, accurate one-sentence answer
Question 1) Why is cooperative binding of oxygen by hemoglobin essential to its function? Please give a concise, accurate one-sentence answer
Subject:BiologyPrice: Bought3
Question 1) Why is cooperative binding of oxygen by hemoglobin essential to its function? Please give a concise, accurate one-sentence answer. Write one sentence only.
Question 2) Most of the CO2 produced in muscle is transported to the lungs independently of hemoglobin. Concisely describe how this CO2 is returned. Does this process require ATP? Why or why not?
Question 3) The crystal structure of a 200 amino acid bacterial protein involved in membrane receptor signaling is solved. It reveals a compact, seven-stranded parallel beta sheet with numerous alpha helices packed on both sides of the sheet. The hydropathy index is quite positive over two stretches of 20-30 amino acids. Sequence alignments of this protein with the same protein found in dozens of other Bacteria shows that these windows are always present, but often not in the same positions along the sequence.
(a) (5 pts) Does the crystal structure suggest that this is likely to be an integral membrane protein? Explain.
(b) (5 pts) Assume that the protein does not span the bilayer. How do you then account for the hydropathy data?
(c) (5 pts) Since you know the protein is involved in a membrane process, how might you experimentally determine its orientation with respect to the bilayer?
Question 4) If exactly half the amount of a weak acid in solution is ionized at a pH of 5.0, what is the pKa of the weak acid? Justify your answer in terms of the Henderson-Hasselbach equation.
Question 5) Consider two extracellular proteins that each bind the same heavily sulfated integral membrane glycoprotein that extends away from the plasma membrane of a cell. Extracellular Protein 1 (EP1) has a large number of arginine residues exposed on its binding surface, while Extracellular Protein 2 (EP2) has a similar number of arginines at the bottom of a deep cleft. EP1 binds the sulfated sugars without large conformational changes, whereas EP2 rearranges to partially close the cleft, excluding solvent.
Is EP1 or EP2 likely to bind the sulfated glycoprotein tighter, and why?
