This investigation is about the actions of enzymes in milk. Aim-To investigate the outcome of rennin enzyme on milk at different temperatures Hypothesis-The temperature increases the time as it takes the rennin to coagulate the milk will decrease, however the temperature continues to rise, the time it takes the rennin to coagulate the milk will begin to decrease as the rennin enzyme starts to denature. Variables-Independent- Temperature of the milkDependent- Rate of reactionControlled- • The quantity of rennin placed in milk • Quantity of milk • Type of milk (full cream)• Type of enzyme (rennin)For this investigation, you will need-• A measuring cylinder that shows 2ml gradations• Two 80ml or 100ml beakers• Bunsen burner• A wire gauze mat• A tripod• Tablets containing the enzyme solution• A thermometer• 50 ml of milk (full cream) in two different beakers• kitchen lighter (optional)First collect and organize the apparatus needed for this investigation.

The milk should be 50 ml (eye – level), then light the Bunsen burner to heat the milk. To set-up the Bunsen burner, first light the burner with a kitchen lighter and shift the burner under the tripod. Place the milk on the gauze mat and wait for the milk to heat and keep holding the thermometer to record the temperature when it reaches to 20oC. Then mix the enzyme solution with the stirring rod. Wait for the milk to cool, since the room temperature is 15oC.

For the first beaker the initial temperature was 14oC in 0 minutes, which looked white and liquid. No change has occurred after 5 minutes. In 10 minutes, the milk was somewhat condensed consistently. In 15 minutes, the milk had solid substances containing proteins, lactose and fats. The solids were chunky and was partially liquid with the solids separated. In 20 minutes, the solid substances in the milk increased into smaller chunks and the liquid the milk was separated and decreased.The initial temperature for the second beaker, the temperature was 18oC in 0 minutes which looked the milk looked white and liquid.

After 5 minutes, the milk was condensed to a creamy and agar like consistency. In 10 minutes, the solid substances started forming and separated with the liquid formed in the milk. In 15 minutes, the condensed milk had a yellow cloudy liquid and the milk became like a jelly.Comparing the two solutions of the chemical reaction between the first and second beaker of milk to curd, the investigation of the action of enzymes in the second solution was faster than the first solution. The major factors to make the activity of enzymes in milk faster, is the temperature and the concentration in an area.