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1)If my protease is in lysosomes and works in the blood to attack un-engulfed in

ID: 186875 • Letter: 1

Question

1)If my protease is in lysosomes and works in the blood to attack un-engulfed invaders at which pH would the protein structure remain relatively intact with the hinge closed?

A) 2.3

B) 5

C) 7.2

D) 7.4

E) 9.5

My Orginial answer choice was 7.2 but Unfortunately that was WRONG. Anyone know the answer? Thanks!

2)  Why do you suppose the EGF repeats form a solenoid, " i.e. a circular/helical surface?"

A) To provide an Enzymatic active site

B) To Provide a Docking Point.

C) To Provide Structural Integraty for interacting cells

D) All Of These

E) None of The above

My orginial answer choice was A. But now that I look at the quesiton again. I think it's D) All of the Above, but I just want confirmation my answer choice!

Thank You!

Explanation / Answer

1) pH 2.3 - For each enzyme, there will be a pH, at which the net charge on the molecule is zero. This is called the isoelectric point (pI), at which the enzyme has minimum solubility in aqueous solutions. The isoelectric point of protease is pH 2.3 or lower. So, at this pH the protein structure will remain intact with the hinge closed. The pH of cytosol is 7.2.