Enzyme Practical Investigation (1 Viewer)

[shiksaxelle]

Hey guys, I do HSC Biology and am having trouble on this task
The Task is:

'Identify data sources, plan, choose equipment and perform a first-hand investigation to test the effect a change in pH has on the activity of a named enzyme.'

I'm terribly confused and not sure where to go. Would anybody be so kind as to talk me through it or suggest which enzyme I should use and how to perform it?

Thank you so much in advance.
x

 

[shiksaxelle]

*I am thinking my enzyme will be amylase, and I will use human saliva for that.
Would that be okay?

 

[RockstarUnknown]

Doing this experiment a couple of weeks ago, we used crushed liver in water, after the liver being added, added to different pH solutions, that worked quite well, depending on which pHs you use.

 

[badalice-tag]

you can use kidney which has the enzyme catalase in it. The substrate is the hydrogen peroxide. you then add different pH including distilled water which has a pH of 7 (neutral)
time the reaction until it ceases and you should also measure the foam that is formed every minute so you are keeping track of the rate of the reaction as well.

 

[shiksaxelle]

you can use kidney which has the enzyme catalase in it. The substrate is the hydrogen peroxide. you then add different pH including distilled water which has a pH of 7 (neutral)
time the reaction until it ceases and you should also measure the foam that is formed every minute so you are keeping track of the rate of the reaction as well.

Thanks so much guys.
I'll use the liver.
So i get water, pour levels of hydrogen peroxide in the water, meseaure the pH, then add it to the kidney?

What will happen to the kidney? What reaction should I be looking for?

Apologies for sounding slow, I'm just trying to make sure I really understand it.
Thanks so much again.
x

 

[spammy679]

we just used hydrogen peroxide and catalase in the form of potato
after a few mins, it starts foaming up

 

[badalice-tag]

ok you dont need water. So you get say 5 test tubes. Label from 1 - 5. put ten mL of the same concentration of Hydrogen peroxide in each test tube. Then choose your different pH levels say 3, 5, 7, 9 and 11. Put ten mL of each of those in the appropriate test tubes. Then one at a time put a chunk (kinda the same size chunk) of kidney in a test tube. Make sure you time the reaction. What will happen is it'll froth up like bubble bath so measure the hight of the foam column every minute whilst timing and record in a table so you have the rate at which the kidney or catalase is reacting with the hydrogen peroxide (substrate). the only one you need water for is pH 7 because distilled water has a pH of 7. hope that helps.

 

[shiksaxelle]

ok you dont need water. So you get say 5 test tubes. Label from 1 - 5. put ten mL of the same concentration of Hydrogen peroxide in each test tube. Then choose your different pH levels say 3, 5, 7, 9 and 11. Put ten mL of each of those in the appropriate test tubes. Then one at a time put a chunk (kinda the same size chunk) of kidney in a test tube. Make sure you time the reaction. What will happen is it'll froth up like bubble bath so measure the hight of the foam column every minute whilst timing and record in a table so you have the rate at which the kidney or catalase is reacting with the hydrogen peroxide (substrate). the only one you need water for is pH 7 because distilled water has a pH of 7. hope that helps.

Gah! You are my hero. Thank you so much for that. I will do this one.
Just one question, what do you mean by 'choose your different pH levels'...where are my pH levels?
x

 

[badalice-tag]

well we did this experiment at school so the teacher had bottles with what i can only describe as "stuff" inside which all had different pH levels.

 

[Jayson89]

Here's another one.

Method:

1) 10mL of hydrogen peroxide was added to each of 5 test tubes

2) Universal indicator was added to each test tube

3) Hydrochloric acid or sodium hydroxide was added to each test

tube and colour changes noted, so that the test tubes had pH’s of

about 2, 4, 7, 10 and 12

4) 5 small cubes were cut from a potato, all about the same size,

using a scalpel

5) One potato cube was placed in each test tube with hydrogen

peroxide. Potato cubes provided the catalase enzyme which

catalyses the decomposition of hydrogen peroxide into oxygen and

water

6) After 5 minutes, the height of foam formed was measured for each test tube

 

[Siretlaw]

Or you know, Milk and Rennin (Renin, however you spell it)...