TBR: Ribozymes

[justadream]

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TBR Bio Book II page 448 #12

“If the right ribozymes attacked an animal cell, which structures could be damaged?”

Answer: Ribosome, Transcript copy of DNA, Amino Acid Carrier for protein translation



I agree with the answer.



TBR says that the question was designed to make sure we know the roles of the 3 types of RNA. I have an issue with this.



Technically, aren’t ribozymes simply RNA molecules that are CATALYSTS. TBR seems to imply that ribozymes can only affect RNA molecules. Since riboyzmes are catalysts, is it not possible that ribozymes can affect non-RNA molecules?

 

[sillyjoe]

TBR Bio Book II page 448 #12

“If the right ribozymes attacked an animal cell, which structures could be damaged?”

Answer: Ribosome, Transcript copy of DNA, Amino Acid Carrier for protein translation



I agree with the answer.



TBR says that the question was designed to make sure we know the roles of the 3 types of RNA. I have an issue with this.



Technically, aren’t ribozymes simply RNA molecules that are CATALYSTS. TBR seems to imply that ribozymes can only affect RNA molecules. Since riboyzmes are catalysts, is it not possible that ribozymes can affect non-RNA molecules?

Ribozymes are RNA molecules that act as enzymes. I only know of examples of ribozymes that catalyze reactions with RNA molecules. I am pretty sure that they only work on RNA, which is why TBR only gave those examples.

 

[drechie]

I concur... I took the question of asking: which type of RNA is mRNA. Anyone have any insight into rethinking this question

 

[referee3]

Ribozymes only cleave RNA. So your text book is correct.


Additional fun fact: they were discovered by Thomas Cech who won the 1989 Nobel prize in chemistry for this discovery and currently teaches at The university of Colorado.

 

[NextStepTutor_1]

Yes I agree with @sillyjoe. I understand ribozymes to be RNA enzymes, as opposed to peptide enzymes, that only work with reactions of RNA molecules. This info is derived from a biochem book I have laying around.

 

[Czarcasm]

Single-stranded RNA has the unique ability to fold upon itself into a 3D shape, allowing it to exhibit some form of specificity. This essentially allows it to function as an enzyme aka "Ribozyme." In this regard, they are similar to protein enzymes, which also exhibit a unique 3D structure. But the major difference between the two, of course, is that protein enzymes are made of aminoacids, while Ribozymes consist of ribonucleotides. And while both exhibit a unique molecular structure, their functions are seemingly very similar.

A classic example of enzyme function involves certain functional groups, such as a hydroxyl (-OH) group, attacking the carboxyl end of an aminoacid (of some substrate, say an aminoacid). Without going into detail, this process lowers the high-energy transition state by stabilizing it, making the reaction proceed more quickly. With this in mind, it should make sense that ribozymes (which also have -OH groups) are not limited to catalysis of RNA molecules. In fact, our ribosomes have an RNA component which functions as a ribozyme; this ribozyme is what allows for peptide bond formation between aminoacids, during protein synthesis.