Factors that affect enzyme activity (pH, temperature, activators and inhibitors)

. The effect of pH on enzyme activityone. Purpose
1. Understand the effect of pH on the speed of enzymatic reaction.
2. Master the principle and qualitative method of determining the activity of salivary amylase.two. Principle
1. Enzymes: A protein produced by living cells that act as an efficient catalytic agent on
specific
.
2. Enzymatic reaction: A chemical reaction that is catalyzed by an enzyme.
3. Factors that affect the speed of the enzymatic reaction: s, e, pH, temperature,
ortiates and inhibitors
In the pH range that does not cause denaturation, the activity of the enzyme will vary depending on the pH. Since an enzyme is a protein, at different hydrogen ion concentrations, its dissoluption is different, but often only one case is the highest vitality of the enzyme, at which point the pH is called the most appropriate pH of the enzyme. If its action condition deviates from any aspect of the most suitable pH, it will cause the enzyme activity to decrease and slow down the enzyme-promoting reaction speed.
Salivary amylase can make starch water into a series of relatively simple
compound
, the final product is maltose, using its different color reaction with iodine, you can deduce the degree of amylase hydrolytic starch and pH on the activity of salivary amylase, and can point out the most suitable pH of salivary amylase.


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. Starch → Purple Dedexion → Red Dedexion → Maltose
(when iodine is blue, when iodine is purple, when iodine is red, when iodine is pale yellow)
saliva prepared:
flower
with a thin layer of cotton will be put Placed on top of 10 ml
barrel
, more than 5 students spit 1 ml of saliva, poured into 100 ml of drum, rinsed with distilled water into a large number of cylinders, add distilled water to 100 ml, mix saliva with suction tube.
take
test tube
3, number, according to the table plus a variety of
reagents
.
Shake well into a 37-degree C water bath to keep warm for 3 minutes, use a dropper to absorb pH6.8 tube liquid drops, in the white porcelain plate with iodine liquid to check whether the hydrolysing is complete, and then to each tube iodized liquid 3 drops, observation results explained.effect of temperature on enzyme activity
one. Objective to
the effect of temperature on enzyme activity.two. Principle
At low temperatures, the rate of catalytic reaction of enzymes is generally very low, and the rate of catalytic reaction of temperature increases, but enzymes are a protein, and increasing temperature can cause protein denaturation, which reduces the activity of enzymes. Therefore, temperature has two opposite effects on enzyme activity, generally in the relatively low temperature range (e.g. 0-40 degrees C), temperature has little effect on enzyme protein denaturation, activity increases with temperature. All enzymes have their most suitable temperature, at which point the enzymes show the highest vitality. The maximum temperature of most enzymes in the body is 37 degrees C to 40 degrees C. In this experiment, iodine and starch reactions were used to compare the hydrolytic velocity of salivary amylase to starch at different temperatures


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