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16 Cards in this Set
- Front
- Back
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what is an enzyme |
An enzyme is a protein that speeds up (catalyze) the rate of a metabolic reaction by lowering the activation energy |
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what is the activation energy? Why does it need to be lowered? |
The activation energy is the initial energy needed for a reaction to take place. If the activation energy is super high, its harder for a reaction to take place because it needs lots of energy. If activation energy is low not a lot of energy is needed for a reaction to initiate. |
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What is a substrate |
a substrate would be the key if the enzyme was a lock. without a substrate a reaction can't take place. |
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whats an enzyme-substrate complex |
the enzyme and substrate bind tightly together through covalent bonds creating an enzyme-substrate complex. Then a product is formed which detaches from the enzymes. |
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how does a reaction speed up |
the more substrates the faster enzymes bind to them. However, as soon as all the enzymes are paired up the reaction rate remains constant |
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Effects of temp on enzymes |
so the temp does two things. 1. the higher the temp the faster the molecules move around and the quicker they find substrates to bind with. (The rate of reaction typically doubles with each 10c) 2. it can distort the shape of the enzyme once it reaches its optimal temperature. |
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Potato extract experiment Catechol + Catechol Oxidase = Benzoquinone |
so for this lab we measured the quantitive and qualitative absorbance for benzoquinone at 470nm. The enzyme was catechol oxidase, which was the potato extract. |
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results for potato extract experiment. |
tube 4 was the darkest because it didn't surpass the optimal temp. IT contained the oxidase, catechol, and it was 22c. Tube 7 was the lightest because it was 80c. It surpassed the optimal temp by a lot. |
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hypothesis for potato extract experiment |
The longer the test tubes stayed in the higher the absorbance rate would be. |
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Effects of PH |
Enzyme activity is very sensitive to PH, because the surface and side groups of the enzyme molecule are always charged. The PH can either change the enzymes conformation enough to alter the shape of the active site. It can denature the enzyme just like temp can |
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low vs high PH |
Low Ph the side groups gain H+ and as for Already High PH they lose H+ |
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PH Experiment |
Hydrogen Peroxide is broken down by catalase to water and oxygen 2H2O2 -------catalase---------> 2H2O +O2 |
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Inhibitors |
there are two types of inhibitors 1. Competitive - bind to the active site before the substrate. Since it's not the right key for lock (enzyme), the reaction doesn't happen. 2. Non-competitive - They don't compete for the active site, these sneaky sons of b****** attach to the allosteric site, distorting the shape of the active site. |
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Inhibitor experiment |
Peroxidase converts toxic hydrogen peroxide to H2O and O2. kinda like catalase. Peroxidase can be inhibited by chemicals. Peroxidase has iron atoms at its active site |
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Hyrdoxolamine |
This is a competitive inhibitor which is kinda like hydrogen peroxide but not really because it binds to the iron atoms at the active site of peroxide. This prevents peroxidase to bind with hydrogen peroxide. |
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measuring the production of oxygen by peroxidase to find out the reaction rate. |
Guaiacol turns brown when oxidized. O2 + guaiacol ---peroxidase----> Oxidized guaicol |
