Share
Explore BrainMass

Enzyme Action

1) What is the region of an enzyme structure in which the substrate is attached called? Is it the active site or something else?

2) Is the activation energy of an enzyme-catalyzed reaction greater or less than that for a reaction in which no enzyme is present?

3) What is the difference between a competitive inhibitor and a non-competitive inhibitor?

4) How, if at all, could the effect of the presence of each type of inhibitor be overcome?

5) What effect would, if doubled, cause the rate of reaction to be doubled?

6) Is it true that all enzymes are irreversibly inhibited at about 40C and that they are denatured at pH 3.0 and that a change in the pH of the environment will cause hydrolysis of the polypeptide of an enzyme and that enzymes have an optimum pH at which they will work best?

7) Which metal is poisonous because it inhibts enzymes by oxidizing their cysteine residues? Is it mercury or something else like calcium, magnesium, or iron?

8) Which type of enzyme is Urease (H2N-C-NH2 + H2O <------> 2NH3 + CO2)

9) Which type of enzyme is Phosphoglyceromutase (-OOC-CHOH-CH2-OPO3 2-
<--------> -OOC-CH-CH2-OH)
|
OPO3 2-

10) Which type of enzyme is Succinate dehydrogenase (-OOC-CH2-CH2-COO- + FAD <-----------> -OOC-CH=CH-COO- + FADH2)

11) Which type of enzyme is Aspartase (-OOC-CH=CH-COO- + NH4+ <--------->
-OOC-CH2-CH-COO-)
|
NH3+

Solution Preview

1) What is the region of an enzyme structure in which the substrate is attached called? Is it the active site or something else?

Response: Yes, it's called the "active site." This is where the catalytic event (biochemical mechanism) takes place.

2) Is the activation energy of an enzyme-catalyzed reaction greater or less than that for a reaction in which no enzyme is present?

Response: The activation energy is always less when the enzyme catalyzes the reaction. That's how the reaction gets sped up. Less energy is needed to reach transition state.

3) What is the difference between a competitive inhibitor and a non-competitive inhibitor?

Response: A competitive inhibitor binds to the active site and prevents the substrate from binding whereas a non-competitive inhibitor binds elsewhere on the surface of the enzyme thus disabling the enzyme but not preventing substrate binding. If you're familiar with enzyme kinetics a little bit, another way to look at it is like this: a competitive inhibitor does not change Vmax, just Km; whereas a noncompetitive ...

Solution Summary

This solution provides various problems regarding enzyme action.

$2.19