User talk:Study of fruit juice

Study of fruit juice is an experiment

Objective
To investigate the presence of protease in different fruit juices

Background
Fresh juice contains protease, a kind of enzyme which can make beef soft because it can speed up the breakdown of proteins in the beef. The experiment is to find out the amount of protease in different fruit juices.

Study of fruit juice, investigate the presence of protease in different fruit juices
Study of fruit juice is an experiment to investigate the presence of protease in different fruit juices

Objective
To investigate the presence of protease in different fruit juices

Background
Fresh juice contains protease, a kind of enzyme which can make beef soft because it can speed up the breakdown of proteins in the beef. The experiment is to find out the amount of protease in different fruit juices.

Independent variable
It is the variable to be changed. Different samples are put into the holes of the milk-agar plate to see the reaction.

Dependent variable
It is the variable that may change depend on the independent variable, it is also the variable to be measured. The size of the area of clear zone in the milk-agar plate is measured with a piece of graph paper after the samples are put into the milk-agar plate for one day.

Control variable
It is the variables that are kept the same during the experiment. Temperature is one of the control variables. The temperature of the samples must be kept the same to ensure the reaction of the samples is fair. The size of the holes in the milk-agar plate are kept the same to prevent inaccurate measurement. The same amount of samples are put into the agar-plate to give a fair result.

Control
The control (distilled water) is put together with the fruit juices into one of the wells in the milk-agar plate to compare with the results of the samples. This is a control to show that the reaction is due to the presence of protease.

Apparatus and Materials
Cork borer X1 	Graph paper X1 Dropper X5 	Marker pen X1 Test tube holder X1 	Incubator X1 Milk-agar plate X1	Distilled water Papaya juice Guava juice Pineapple juice Kiwi fruit juice Hot water

Procedures
a)	A cork borer was heated in hot water for sterilizing and was allowed to cool. b)	Milk-agar plate was dug five wells with the cork borer. c)	The plate was covered at once. d)	The wells in milk-agar plate were labelled by marker pen on the side of the Petri dish to indicate the arrangement of samples. e)	Wells A to E were filled up by five clean droppers with distilled water, papaya juice, guava juice, pineapple juice and kiwi fruit juice respectively. f)	The lid was replaced. g)	The milk-agar plate was put into incubator for half day in order to keep it at 37 °C . h)	The diameter of clear zones near the wells were measured with graph paper under light. i)	The measured data were marked by marker pen and a table was made.

Results
Wells	Samples	           Diameter of clear zone ( Number of squares in graph paper ) A	Distilled water	       0 B	Kiwi fruit juice	11 C	Pineapple juice	       9 D	Guava juice	       6 E	Papaya juice	       5

Principle of experiment
The clear zone appears because milk-agar plate contain a substance which is called casein, made the color of the milk-agar plate white. After the protease in fruit juices diffuse into the milk-agar plate, the proteins in the milk-agar plate were digested by the proteases since protease is an enzyme which can cause breakdown reaction between protease and proteins. After that, the white color of milk-agar disappeared because the breakdown reaction between proteases and proteins, the colorless clear zone appeared near the wells. Distilled water does not have any protease, so it is no reaction between proteins in milk-agar plate and distilled water. The milk-agar plate must be put into incubator at 37 °C for half day before we measure the diameter of clear zone, that is protease is a kind of enzyme, enzymes will be denatured at extreme high temperature, so protease cannot react with proteins at extreme high temperature, when it is low temperature, the enzymatic activity is low, at optimum temperature, enzymes work best, the enzymatic activity is the highest. The optimum temperature of protease is 37 °C, protease work best at 37 °C, the milk-agar plate must be keep at incubator at 37 °C in order to get the best result, the larger the area of clear zone, more accurate result can get for comparison, it can also have easier measurement.

Data analysis
After we collect the data, it is shown that kiwi fruit juice has the largest area of clear zone between five different samples, the diameter of clear zone of kiwi fruit juice is 11 squares in graph paper, the second of it is pineapple juice, the diameter of clear zone of pineapple juice is 9 squares in graph paper, the third of it is guava juice, it’s diameter of clear zone is 6 squares in graph paper long, the fourth between these five sample is papaya juice, the length of clear zone of papaya juice only has 5 squares in graph paper long, the last of these five samples is distilled water, it does not has clear zone, so the length of it’s clear zone is zero squares in graph paper. The result of this experiment happens because kiwi fruit juice has the highest concentration of protease between five sample in same volume while the other fruit juices has less protease in the ratio of the juice compare with kiwi fruit juice, so the diameter of clear zone compare with kiwi fruit juice is relativity smaller. Distilled water only has water (H2O) molecules in this sample, it virtually does not react with proteins, no reaction can be seen.

Study of fruit juice
Study of fruit juice is an experiment

Objective
To investigate the presence of protease in different fruit juices

Background
Fresh juice contains protease, a kind of enzyme which can make beef soft because it can speed up the breakdown of proteins in the beef. The experiment is to find out the amount of protease in different fruit juices.

Study of fruit juice, investigate the presence of protease in different fruit juices
Study of fruit juice is an experiment to investigate the presence of protease in different fruit juices

Objective
To investigate the presence of protease in different fruit juices

Background
Fresh juice contains protease, a kind of enzyme which can make beef soft because it can speed up the breakdown of proteins in the beef. The experiment is to find out the amount of protease in different fruit juices.

Independent variable
It is the variable to be changed. Different samples are put into the holes of the milk-agar plate to see the reaction.

Dependent variable
It is the variable that may change depend on the independent variable, it is also the variable to be measured. The size of the area of clear zone in the milk-agar plate is measured with a piece of graph paper after the samples are put into the milk-agar plate for one day.

Control variable
It is the variables that are kept the same during the experiment. Temperature is one of the control variables. The temperature of the samples must be kept the same to ensure the reaction of the samples is fair. The size of the holes in the milk-agar plate are kept the same to prevent inaccurate measurement. The same amount of samples are put into the agar-plate to give a fair result.

Control
The control (distilled water) is put together with the fruit juices into one of the wells in the milk-agar plate to compare with the results of the samples. This is a control to show that the reaction is due to the presence of protease.

Apparatus and Materials
Cork borer X1 	Graph paper X1 Dropper X5 	Marker pen X1 Test tube holder X1 	Incubator X1 Milk-agar plate X1	Distilled water Papaya juice Guava juice Pineapple juice Kiwi fruit juice Hot water

Procedures
a)	A cork borer was heated in hot water for sterilizing and was allowed to cool. b)	Milk-agar plate was dug five wells with the cork borer. c)	The plate was covered at once. d)	The wells in milk-agar plate were labelled by marker pen on the side of the Petri dish to indicate the arrangement of samples. e)	Wells A to E were filled up by five clean droppers with distilled water, papaya juice, guava juice, pineapple juice and kiwi fruit juice respectively. f)	The lid was replaced. g)	The milk-agar plate was put into incubator for half day in order to keep it at 37 °C . h)	The diameter of clear zones near the wells were measured with graph paper under light. i)	The measured data were marked by marker pen and a table was made.

Results
Wells	Samples	           Diameter of clear zone ( Number of squares in graph paper ) A	Distilled water	       0 B	Kiwi fruit juice	11 C	Pineapple juice	       9 D	Guava juice	       6 E	Papaya juice	       5

Principle of experiment
The clear zone appears because milk-agar plate contain a substance which is called casein, made the color of the milk-agar plate white. After the protease in fruit juices diffuse into the milk-agar plate, the proteins in the milk-agar plate were digested by the proteases since protease is an enzyme which can cause breakdown reaction between protease and proteins. After that, the white color of milk-agar disappeared because the breakdown reaction between proteases and proteins, the colorless clear zone appeared near the wells. Distilled water does not have any protease, so it is no reaction between proteins in milk-agar plate and distilled water. The milk-agar plate must be put into incubator at 37 °C for half day before we measure the diameter of clear zone, that is protease is a kind of enzyme, enzymes will be denatured at extreme high temperature, so protease cannot react with proteins at extreme high temperature, when it is low temperature, the enzymatic activity is low, at optimum temperature, enzymes work best, the enzymatic activity is the highest. The optimum temperature of protease is 37 °C, protease work best at 37 °C, the milk-agar plate must be keep at incubator at 37 °C in order to get the best result, the larger the area of clear zone, more accurate result can get for comparison, it can also have easier measurement.

Data analysis
After we collect the data, it is shown that kiwi fruit juice has the largest area of clear zone between five different samples, the diameter of clear zone of kiwi fruit juice is 11 squares in graph paper, the second of it is pineapple juice, the diameter of clear zone of pineapple juice is 9 squares in graph paper, the third of it is guava juice, it’s diameter of clear zone is 6 squares in graph paper long, the fourth between these five sample is papaya juice, the length of clear zone of papaya juice only has 5 squares in graph paper long, the last of these five samples is distilled water, it does not has clear zone, so the length of it’s clear zone is zero squares in graph paper. The result of this experiment happens because kiwi fruit juice has the highest concentration of protease between five sample in same volume while the other fruit juices has less protease in the ratio of the juice compare with kiwi fruit juice, so the diameter of clear zone compare with kiwi fruit juice is relativity smaller. Distilled water only has water (H2O) molecules in this sample, it virtually does not react with proteins, no reaction can be seen.