Enzyme properties

, the purpose isto deepen the understanding of the properties of enzymes. , content,(-) temperature on enzyme vitality1. Principle:
the catalysis of the enzyme is influenced by temperature, and the enzyme reacts most quickly at the most suitable temperature. The maximum temperature of most animal enzymes is 37 to 40 degrees C, and the maximum temperature of plant enzymes is 50 to 60 degrees C. The stability of enzymes to temperature is related to the form in which enzymes exist. Some enzymes
dyring
preparations, although
heating
to 100 degrees C, its activity did not change significantly, but in a solution of 100 degrees C is quickly completely inactive. Low temperatures can reduce or inhibit the activity of enzymes, but they do not inactive.
2. Equipment
1
test tube
and test tube rack
2
ring temperature
water bath
3 s ice bath
s4 s boiling water bath
3.
reagents0.3% sodium chloride solution of 1 0.2% starch: now equipped with
200 times diluted saliva



3 potassium iodide-iodine solution
20g potassium iodide and 10g iodine are dissolved in 100ml of water and diluted 10 times before use.
4. How to
starch and soluble starch are blue with iodine. According to the size of its molecules, iodine may be blue, purple, dark brown or red. The simplest paste was iodine without color, and maltose was not colored when iodine was met. At different temperatures, the degree to which starch is hydrolyzed by salivary amylase can be determined by the color of the hydrolyzed mixture in iodine.
take 3 test tube numbers, add 1 ml starch solution, 1 2 tubes each add diluted saliva 1 ml, 3 tube for boiling saliva 1 ml shake well. Put the 1st and 3rd test tubes into a heated water bath at 37 degrees C, tube 2 into ice water, take out after 10min, divide the liquid in tube 2 into two parts, and use potassium iodide-iodine solution to test the degree of starch in the 1, 2 and 3 tubes hydrolyzed by salivary amylase, record and explain the results. After putting the remaining half of the solution of tube 2 into the water bath at 37 degrees C and continuing to keep warm for 10min, the results are recorded with iodine liquid.(ii) pHeffects on enzyme activity 1. The principle
the vitality of the enzyme is greatly affected by environmental pH. The most appropriate pH for different enzymes is different. For example, the most suitable pH for salivary amylase is about 6.8. However, the most suitable pH of the enzyme is affected by the properties of the substrate and buffer.
2. Equipment
1 test tube and test tube rack
2 tube
3) dropper
4 tubular bottle
5 sr. thermostat water bath