Heavy metal ions such as mercury and silver inhibit many enzymes irreversibly because they
Correct answer: D. bind to the sulphydryl groups of the protein and destroy its shape
- A. compete with the substrate for the active site
- B. raise the pH of the solution
- C. supply the enzyme with excess energy
- D. bind to the sulphydryl groups of the protein and destroy its shape
Explanation
These ions attack the sulphur containing side chains, breaking disulphide bridges and permanently distorting the tertiary structure, so the damage cannot be reversed by removing the inhibitor or adding more substrate. This is essentially poisoning rather than regulation, and it is why mercury contamination is so dangerous. A competitive inhibitor, by contrast, binds reversibly at the active site.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
About Enzyme Inhibitors
Enzyme inhibitors reduce reaction rate by interfering with enzyme-substrate interaction or catalytic activity. Coverage includes reversible competitive, non-competitive and uncompetitive inhibition, the effects of inhibitor concentration on reaction rate, and why competitive inhibition can be reduced by increasing substrate concentration.
Practise Enzymes
633 free Enzymes MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Biology questions like this
Biology is on 8 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Enzyme Inhibitors questions
Malonate inhibits succinate dehydrogenase because it resembles succinate. This is an example of
Increasing the substrate concentration will NOT relieve the effect of
A competitive inhibitor slows an enzyme catalysed reaction by
In feedback inhibition of a metabolic pathway
An allosteric site on an enzyme is
Compared with the uninhibited enzyme, a non competitive inhibitor