Just adding to what AliceD has said, something I've frequently seen is questions that are something along the lines of (and yeah, this is a simple copy paste from a quick Google search for sample biology questions):
Which of the following statements about enzymes is not true?
- Enzymes are catalysts.
- Almost all enzymes are proteins.
- Enzymes operate most efficiently at optimum pH.
- Enzymes are destroyed during chemical reactions.
what the answer plz help.
While the question is on topic... we're not here to do your homework for you. In order to make this question acceptable, you would have to explain what you have done, and why you seem unable to answer the question. For instance, if you are hesitating between 2 and 4, because you know that enzymes are not destroyed during chemical reactions, but you were pretty sure that enzymes are always proteins, you could post a question along these lines:
So throughout my education and research career I have been taught that all enzymes are proteins. This makes sense when you consider enzyme denaturing and folding/shape etc. However, I was recently told by a biology professor that in fact, not all enzymes are proteins -- and he alluded to the RNA world hypothesis and rRNA's.
Could someone explain further how exactly an rRNA (or similar) could be (or not be) considered an enzyme, and whether or not all enzymes are proteins etc?
Bottom line is that we don't mind helping you understand your homework if you are genuinely trying, but we are not going to spend our time answering every random homework / test question that comes our way.