Question

please help me out!

Effect of pH - Tube 7: 1 ml catalase + pH 3.0 solution - Tube 8: 1 ml catalase + ph 7.0 solution - Tube 9: 1 ml catalase + pH 11.0 solution - incubate at room temp for one minute - add 3 ml H,O, to each tube and mix Question #7: This catalase came from a potato. Like most living organisms, potatoes are water-based. State the NUMBER of the ONE tube that is likely to produce the most bubbles: (this question is not meant to be complicated:-) Effect of temperature - place 1 ml pH 7.0 catalase in each of four tubes: - Tube 4: ice bath (0 C) - Tube 5: room temperature (countertop) - Tube 6: water bath (37 C) - Tube 7: boil (countertop); Incubate 15 minutes before proceeding: - add 3 ml H,O, to each tube; mix Question #8: This catalase came from a potato. But is it a potato that grows in South Carolina? In Idaho? In Siberia? State the NUMBER of the ONE tube that is absolutely NOT going to produce any bubbles: Question #9: State the NUMBER of the ONE tube that would be likely to produce the most bubbles IF this were human being catalase: (See how I snuck in that metric system review? Neat, huh?)

Answer 1

Catalase is one of the highly efficient enzymes. It is a tetramer made of four porphyrin rings and catalyzes the conversion of the DNA damaging agent Hydrogen Peroxide H2O2 into H2 and O2. Hence, when H2O2 is added to catalase in a test-tube, H2 and O2 will be produced whenever the enzyme is functional. Based on the activity of the enzyme and the presence of optimum conditions, the H2 and O2 released would vary with the amount being maximum for optimum conditions. The O2 released will cause bubbles.

Question 7: Being an enzyme in a living cell, it is selected evolutionarily to function at the pH of the cell, which is roughly 7.0. Hence the catalase will produce maximum bubbles at pH 7.0 in tube 8.

Question 8: Again being an enzyme in a living cell, it is selected to function at the temperature of the cell, which is around 37 degrees C. This temperature will vary based on the environment in which the potato grows. Thus it can vary from roughly 0 degrees C near Siberia to hot temperatures up to 50-60 degree C. But it will surely not be active at a temperature of 100 degree C in boiling water, where the protein will be almost completely denatured.

Question 9: In humans, the internal temperature is strictly regulated around 37 degree C. Hence the human catalase will definitely be most active at 37 degree C and produce most bubbles at this temperature.