Hello. Okay this is my first year ever doing biology, so i feel a little behind. I appologise for a long thing and all the questions. I'll number the questions.
We have completed 2 practical experiments on enzymes. The first one was testing the rate of reaction between Liver Catalase and hydrogen peroxide in 3 different pH buffers (4, 7 & 10).
The second one was testing the rate of reaction between Liver Catalase and hydrogen peroxide at 4 different temperature; Ice cold, room temp., 40 degrees, and 80degrees. Although, what we did was put the test tubes with Liver in water in a bath of each of those temps for 10 mins and then we had to let them all sit to return to room temperature. 1. So i'm guessing the aim wasn't to see how temperature effects the rate of reaction, but instead how temperature effects the enzyme in a way which in turn effects the reaction rate? Unless that's legit the same thing idk.
For both practicals, the ROR was tested using a stop watch, a ruler, and a splint. It wasn't specified exactly how to use those tools to measure.
I saw some students timing the reaction up until the bubbles started to dissappear. However i was timing how long it took for the bubbles to reach a maximum height. So i stopped timing when the bubbles stopped going higher and were instead building at the same rate as they dissappeared. 2. Not sure if that's a correct way of doing it?
Then, i assumed that when the bubbles had stopped increasing in height that perhaps that meant the Enzyme was saturated. 3. But if each trial had the same amount of liver and the same amount of Hydrogen Peroxide then shouldnt all the trials have reached the same maximum height but just at different speeds? 4. Most trials had a height difference of between 0.2 and 1cm. Why didn't all the trials climb to the same height? Or is that due to varying degrees of enzyme denaturation?
5&6. Actually, if the bubbles stopped growing in height, could that mean that there is simply less hydrogen peroxide molecues floating around and so less collisions occuring instead of the enzyme being saturated? bc the substrate wasnt increased so i guess the enzyme wouldn't have become saturated?
So i know catalase optimal pH and temperature is 7 and 37 ish degrees right? But i think the reaction was quickest in the room temperature trial compared to the 40 degree one. Thing is, there are discussion questions on this, one of which asks to write the optimal pH and temperature. the pH everyone knows is 7, 7. but how could we know the temperature when the only trial that was close to that temp was the 40 degree one? I originally assumed the optimal would be around 37 degrees bc i know that's basically body temperature and Catalase in inside the body. 8. I'm just confused, does that mean the question is expecting us to apply some logic and know that the body temp is around 37?
I understand that the 80degree trial definitely caused the enzymes to be permanantly denatured, as there was only 0.01cm of bubbles produced and there was no oxygen when we used the splint. 9. But what exactly would the ice water have done to the enzyme? I at first thought that cold temperatures just slow everything down. But after bathing the liver in ice water, we left it to go to room temperature, so wouldn't that speed things back up a little? 10. Or does the cold temperatures have a long lasting effect on the enzyme even after warming up to room temperature (which may have been higher than 20 degrees because it was a fairly warm day)? i should add, there was a reaction with the ice trial, it was slower than the room temp and 40 degree trial but it still seemed to be just as reactive as those two, but it slowed down quicker and reached a lower bubble height.
11. Basically, how does the cold temp effect the actual enzyme structure? or does it just slow it down. this one really confused me.
Half of this probs makes no sense. Sorry for the detail, i've never been good at being concise.