Science Buddies: "Ask an Expert"

I'm doing a lab that involves breaking down hydrogen peroxide with the enzyme catalase. I used three different liver samples (beef, pork, chicken) for the experiment. The results show that the beef has the highest rate of reaction, the pig has the second, and the chicken is the slowest. I need to provide reasoning behind these results, but I'm not sure if I have the right idea. I said that since the cow is the largest animal and ingests the most food, its liver is of course larger and must have a high rate of reaction of process the large quantities faster. Progressively, the pig and chicken follow. Am I on the right track?

Hi Ivana,

I am sorry it took a few days to reply to you. Yes, I think you are on the right track. From what you said, keep going with the idea:

must have a high rate of reaction of process the large quantities faster.

How does it process faster? Could there be more enzyme present in the beef liver, driving the reaction more quickly? What enzyme would that probablly be? Could you check anywhere to see if anyone has measured the catalse in different livers?

Let me know if you have more questions. Good luck on your project!
Tonya

Hi Ivana,

Tonya has already given you some great advice! I have a couple more things you can consider. As you hypothesized and Tonya mentioned, a larger liver could simply mean more enzyme is present. However, the enzyme catalase may have different versions in different animals. Have you considered that the enzyme may be different in mammals (cows and pigs) compared to birds (chickens)? Just some ideas to get you thinking.

Heather