Question

What causes the lack of on in tube # 5 that is acting as the control tube? 13. What is the reason for using the control tube What is the reason for 5. used in this exercise 14. What is the relationship between the concentration of pepsin and enzyme activity, as observed on Figure 3-7? 15. How does an increase in the amount of the pepsin, in the test tube, enhance the interaction between pepsin and substrate, thus speeding up its enzyme activity?

Answer 1

Answer (12) .In tube no. 5 there is no clarification because no pepsin enzyme was added to this test tube so only albumen was there . Without proteases albumen could not be digested and pepsin is the protease used.

Answer (13) Control tube is used without enzyme . It is used because we are studying the effect of enzyme on its substrate albumen (egg white). In test tube no 5 no enzyme is added just to check that clarification process is related only to enzyme or something else .

Answer (14). In given experiment enzyme concentration decreases as we move from tube 1 to tube 4. Generally enzyme activity decreases with enzyme dilution as no. of active sites occupied by substrate become less .

Answer (15). As we increase enzyme concentration no. of active sites available for binding to substrate (albumen or egg white protein) increases and more of substrate can be bound . Enzyme activity is dependent on no. of enzyme substrate complexes formed so as these complexes increases in number enzyme activity increases.

Answer (16) pH of 1N HCl will be 1.1 as per definition of pH which is equal of negative log of hydrogen ion concentration . Optimum pH of this enzyme will be around this pH only as enzyme will have more activity at this point .

Answer (17) At high pH conformation change takes place in such a way that binding of substrate to enzyme decreases thus activity of enzyme too decreases .

Answer (18)Pepsin is activated in acidic medium of HCl where it achieve its native conformation to bind to it's substrate maximally and form product efficiently .Any drastic change in pH like increase or decrease in pH or temperature affect native conformation , binding process and finally formation of enzyme substrate complex .Therefore Pepsin is not functional in high pH of blood 7.4