AP Biology Lab 2: Enzyme Catalysis

Paul Andersen starts with a brief description of enzymes and substrates. He then explains how you can measure the rate of an enzyme mediated reaction. Catalase from yeast is used to break hydrogen peroxide down into water and oxygen. He also explains how temperature and pH could affect the rate of a reaction.

Intro Music Atribution
Artist: CosmicD
Creative Commons Atribution License

[astridjohnson]

You're a lifesaver! I genuinely thought I was going to fail this lab, and pull my B to a C or D. Thanks so much for the simple explanation 😊

[rosaruizD]

thank god i found this the friday before the exam! i will watch EVERYTHING and pray to god that i pass! good luck to everyone taking the exam!

[angela]

It's hard to find a good teacher.. This guy ROCKS!!!

[aponed]

lol i think its funny how all his endings are so abrupt

[AngeloTakoyaki]

It's 2016 but I still think his animations are great

[katiepusz]

Thanks for helping me pass college biology(: Keep making videos, please!!

[bryantlim]

Sorry if this is a bit late but, H2SO4 stops the reaction because it's a strong acid. Because of this, it quickly breaks up into the ions H+ and SO4 2-. Now the H+ ions lower the pH of the solution and since the amino acids that comprise proteins are generally suited for neutral or slightly acidic/basic environments the folding of those amino acids into their native structures (secondary, tertiary, quaternary) are disrupted, and the protein, in this case catalase, in this case is denatured.

[jillybrownie]

For anyone watching this 11 years later, there’s something I want to clarify about this video

First off, the enzyme and substrate do not fit like lock and key. A better analogy would be a glove; the enzyme and substrate shapes slightly change in order to fit each other, but not too large extent. This means that what he said about enzymes and substrates not changing she is actually wrong. However, I guess that’s an easier way to understand it, but it may not be good for high school and higher

[hollymolly]

Is it possible to have a similar experiment to test the effect of substrate concentration?
Can we dip the filter paper in different concentrations of hydrogen peroxide and drop them in a fixed concentration of yeast?

[iheartbigbang]

Thank you SO MUCH!!!! your videos helped me!! hope I pass tomorrow...><

[mildredmayorga]

How much concentration of yeast did you use for each which one was the starting concentration and how did you increase

[Jungys]

What about if there was more salt concentration added the same amount of yeast, same amount of normal hydrogen peroxide? You know like if IF MORE OR LESS salt concentration was added? Would it destroy the enzyme if more salt was added or if small amount of salt was too?

[asliyase]

I'm studying the IB program, so I just wanted to ask if this is too simple. Isn't this more appropriate for middle school?

[Glenys]

Thank you very much! This helped me a lot :)

[ВладимирЧернов-чо]

why is it that the greater concentrations takes less time to float up

[nellyt]

I letrally get excellence's and merits because of your wonderful teaching and I'm black :O

[standupshit]

how do you change the concentration of yeast ??

[mildredmayorga]

Hello how did you know what the molarity of yeast would be used

[daniellemyers]

so is it competitive inhibitors that are overcome by the addition of more substrate?

[rennawolfe]

does anyone happen to have a detailed lab protocol that they could share with me for this lab? we've done a different version of this lab but I like to yeast idea...thanks for the phenomenal videos, Paul!!