Apple slices and peeled potatoes rapidly brown in open air due to the presence of phenolases. Phenolases cause the oxidation of phenolic molecules like tyrosine to quinones, colored molecules responsible for the brown colors seen. An experiment comparing the time it took for a change to occur in the color of apple slices versus potato slices was done to test for phenolase activity. Then, a second experiment was done with new apple and potato slices with H2O2 measuring time until bubbles appeared.

b. Which sample contains more catalase? Why?

Question

Apple slices and peeled potatoes rapidly brown in open air due to the presence of phenolases. Phenolases cause the oxidation of phenolic molecules like tyrosine to quinones, colored molecules responsible for the brown colors seen. An experiment comparing the time it took for a change to occur in the color of apple slices versus potato slices was done to test for phenolase activity. Then, a second experiment was done with new apple and potato slices with H2O2 measuring time until bubbles appeared. <IMAGE>

b. Which sample contains more catalase? Why?

b. Which sample contains more catalase? Why?

Accepted Answer

Everybody. And welcome back. Here's the next problem in the biochemistry. Lab students conducted an experiment to compare the enzyme activity in spinach and lettuce leaves. They first observed the color change in both leaves when exposed to air due to phey lase activity. Then they performed another experiment where they added hydrogen peroxide h2o 2 to fresh spinach and lettuce samples and recorded the time until bubbles appeared, which sample has more catalyse. Explain your answer. We have a little table here, the headings enzyme spinach lettuce. So in the first row, we have pal ace as the enzyme with spinach listed as 180 seconds. Lettuce is 150 seconds and catalase as the second row with spinach at seven seconds and lettuce at 15 seconds. Now notice we've got some distracting information here. We don't actually need any of the Phey ace information because our question is saying which sample has more catalase. So the pal ace information is just kind of extraneous, it's there to distract us. So we want to focus on this second row of the chart. So we see that spinach has bubbles appear in seven seconds and lettuce in 15 Well, what does that mean? We need to think about catalyse. So, catalase as an enzyme breaks down hydrogen peroxide into water. And 02 oxygen and the 02 is going to be a gas. So if you have these leaves containing catalyse in a solution, they're covered in hydrogen peroxide and they show bubbles. Well, those bubbles are the oxygen being produced by the catalyst catalyst catalyzed reaction. So which would you expect to have more catalase the spinach or the lettuce? Well, the answer is the one where the bubbles appear first. So spinach has the most catalyse because those bubbles appeared sooner, which indicates more catalase activity. So more catalase present in the spinach leaves. So that is our answer. We'll see you in the next video.

Verified Solution

Key Concepts

Phenolases

Catalase

Enzyme Activity Comparison