Would catalase be a more effective enzyme in a cell at physiological pH (pH 7.4)

Question

Would catalase be a more effective enzyme in a cell at physiological pH (pH 7.4) or in the stomatch at pH 2? Explain. Do you agree or disagree with the following statement: "We refrigerate our food to kill harmful bacteria. Specifically, refrigeration denatures the bacteria's enzymes. Explain sour reasoning. Irreversible inhibitors form strong bonds to the enzyme thereby permanently stopping enzyme activity. Insecticides, herbicides, and heavy metals like Hg^2+ and pb^2+ are irreversible inhibitors. Do you think that the naturally occurring inhibitors that control enzyme activity in our cells act as irreversible or reversible inhibitors? Explain your reasoning. Silver nitrate and 2-propanol are often used to destroy microorganisms. What do you think is the mechanism of action as they function in this capacity? I

Explanation / Answer

1. Enzymes are mainly affected by temperature, pH and substrate concentration. At optimum pH, temperature and substrate concentration the enzyme work effciently but however when there is a change in a pH above or below their optimum pH, causes an break in intramolecular and intermolecular bonds (denaturing) changing the shape of the enzyme and its activity. Catalase work at a optimum pH of 7 which is a neutral pH. Stomach pH is very acidic hence it will lose activity in this. Hence the cell physiological pH will be most effective for the enzyme.

2. We refrigerate the foods not to kill the bacteria or to denature the enzymes of bacteria rather it helps in decreasing the growth of bacteria in food stuffs. Bacteria need a suitable temperature, substrate, moisture for growth. If this is not going to be happen then the shelf life of foods can be increased.

3. Naturally occuring inhibitors in cells are always reversible because in irreversible reaction the enzyme is completely deactivated and not used. In reversible, it is like the lock and key model, the inhibitor will bind to the active site of the enzyme when there is no need. It will revert back when their concentration is reduced.

4. Isopropanol or 2-propanol acts by dehydrating cells, disrupting membrane and causing a precipitation. 70% solution is effective in killing the bacteria. In case of silver nitrate the silver atoms forms a bond with thiol group of enzymes and cause the deactivation. oxidation of sulphydryl groups and precipitation of proteins are the two mechanism involved in silver nitrate.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.