Enzyme Reactions and Temperature
Purpose
Aim - To determine the effect of temperature on the rate of reaction
of rennin when it reacts with milk to cause coagulation.
Hypothesis - As rennin is naturally found in the human stomach I
believe that the optimal temperature for reaction will be
approximately 37°C as this is the regular human body temperature. This
is shown by the graph below.
[IMAGE][1]
Background Research
Rennin is "an enzyme that catalyses the coagulation of milk, found in
the gastric juice of the fourth stomach of young ruminants and used in
making cheeses and junkets. Also called chymosin, rennet."[2] It is
also found in the gastric juices, or Gastric mucosa, of many other
mammals, including humans. In the human stomach, particularly those of
infants, rennin works to curdle milk so that pepsin, another stomach
enzyme, can further breakdown the proteins into absorbable amino acids
called polypeptides
Several experiments have already been conducted testing similar
hypothesis and having similar aims. All of these experiments had very
similar results. They found that approximately 37°C was the optimal
temperature for rennin, it was at this temperature that the milk
solidified quickest. Below that the reaction would occur far more
slowly, sometimes taking hours to complete, sometimes not reacting at
all. Above 37°C at approximately 45°C the enzyme would become
denatured, and the reaction would never occur, even after the
temperature was lowered back down to 37°C.
Name of enzyme - Rennin
Name of substrate - Milk
Materials
- 50ml of full cream milk.
- 10 small test tubes.
- 5 140ml beakers.
- Access to both hot and cold water supplies.
- Pipettes.
- Junket tablets.
- Mortar and Pestle.
- Distilled water.
- Stopwatch.
- Thermometer.
Procedure
Method
-Using a pipette add 5ml of milk to each of the 10 small test tubes.
Label 5 controls and 5 variables.
-Place 100ml of water into each of the beakers, and using hot and cold
2. A test tube was then filled with 35ml of yeast and placed in the
We used the pipette filler and filled the glucose rinsed pipette to add 10ml of 10% of glucose in test tube 0.
2. Drop a gummy bear into each of your prepared beaker or cup and place the beaker or cup
I will get 5 test tubes and place them into the test tube rack. I will
Animal metabolism consists of the utilization of nutrients absorbed from the digestive tract and their catabolism as fuel for energy or their conversion into substances of the body. Metabolism is a continuous process because the molecules and even most cells of the body have brief lifetimes and are constantly replaced, while tissue as a whole maintains its characteristic structure. This constant rebuilding process without a net change in the amount of a cell constituent is known as dynamic equilibrium (Grolier1996). In the combustion of food, oxygen is used and carbon dioxide is given off. The rate of oxygen consumption indicates the energy expenditure of an organism, or its metabolic rate (Grolier1996).
Equipment list: Test tubes were used to hold the milk, the lipase and the milk and lipase solutions. Test tube racks were used to hold the test tubes
Planning Firstly here is a list of equipment I used. Boiling tubes Weighing scales Knife Paper towels 100% solution 0% solution (distilled water) measuring beakers potato chips Cork borer. We planned to start our experiment by doing some preliminary work. We planned to set up our experiment in the following way.
Plan 1. Collect 4 different sized beakers 2. Boil some water in the kettle 3. Pour 50ml into each beaker 4. After 1 minute check temperature 5.
Put a label on each test tube. With a pencil, number each test tube from one to twelve.
Measuring cylinder to measure small amounts of fluids. Pipette to gather small amounts of fluids. Test tube holder to hold test tubes. 2. Molar Salt solutions to submerge potato chips in.
3.) Divide your 30g of white substance into the 4 test tubes evenly. You should put 7.5g into each test tube along with the water.
== § Test tubes X 11 § 0.10 molar dm -3 Copper (II) Sulphate solution § distilled water § egg albumen from 3 eggs. § Syringe X 12 § colorimeter § tripod § 100ml beaker § Bunsen burner § test tube holder § safety glasses § gloves § test tube pen § test tube method = == = =
The pH of the solution would alter the rate of the reaction if it was
4. Put milk samples into the beaker for about five and a half minutes and take samples out after time is up. 5. With the warm samples, open the pouch containing the gel cassette and remove the cassette.
tube. Add 6 mL of 0.1M HCl to the first test tube, then 0.1M KMnO4 and