D) old and full of holes, but the three brothers
<span> The comment on a peer’s research essay that clearly addresses problems with supporting evidence is D. The reason you discuss in paragraph 2 does not seem to fit with you claim. This comment is very important for giving correct reason that would fit with a claim has direct impact to the research paper. Therefore, this problem should be properly address to make the research valuable.</span>
The answer is 2.
Enzymes work to speed up chemical reactions by changing what goes into the reactions (substrates) into different molecules. To do so, these enzymes bind with the substrates, making the physical form very important. The lock and key method explains that enzymes and their corresponding substrates are shaped very specifically to be able to fit into one another to undergo this change.