Which liver (cow, sheep &fish) will have the most catalase present breaking down hydrogen peroxide?
I would look at this in a slightly different way. First of all looking at cow and sheep I would expect the values obtained say for 1g of each liver to be about the same. I have the following reasons for thinking this: Sheep and cattle are fairly closely related, both ruminants of the family Bovidae – therefore their common genetic ancestry makes it more likely that the DNA sequence and ultimately the structure of their catalase enzymes will be very similar. Second they have a similar diet and lifestyle, so you couldn’t expect diet to be a hugely confounding variable and they might both produce hydrogen peroxide at a similar rate. Ultimately, cattle as the larger animal will have the liver with the largest volume, but will also ingest more food and so I expect that the RATE of breakdown of hydrogen peroxide, i.e. the level of enzyme activity will be the same in both. That is the fundamental thing that you need to measure and you need to use the same amount of liver for both species – as
