This experiment shows one way to find the index of refraction of Jello. Jello is a common delectable treat enjoyed by many kids.
It is also a translucent material which makes it a perfect candidate for an index of refraction experiment.
Index of refraction is one of the most important concepts in optics and is an important basis for many interesting phenomenon. Through this experiment, kids can learn and become interested in science while having fun! Create a semicircle shaped piece of Jello using a semicircle petri dish. Follow instructions on jello box.
Any color may be used. The semicircle shape will ensure accurate and easily detectable and measurable refraction from laser. Set up the experiment by first placing the slider rail on top of the books or a suitable substitute to elevate the jello. Place the protractor holder in the middle of the slider, and then put the protractor on the protractor holder. Place the semi-circle jello petri dish on the protractor. Place the laser at the end of the rail so it points directly at and over the protractor.
Line the Jello up to the 90 degree line so that the laser is perpendicular to the flat jello surface. Rotate the angle measuring platform 10 degrees more each time 10, 20, 30 etc and record the angle that the laser exits the jello on the other side. Repeat this until the laser is hitting the jello at 90 degrees completely parallel. Repeat this step 2 more times for a total of 3 trials. Snell's Law will be used to determine the index of refraction.
Average the refraction angle at each degree measured and create a graph of the sines of refraction angles vs. Create a line of best fit from the data. The refractive index of Jello will be the slope of this line.
Our graph shown above had a best fit line with a slope of 1.
Upon completion of this experiment, we learned many things. We realized that it can be difficult to see the refracted light from a red laser in cherry Jello.Did you know that certain fruits have enzymes that when mixed with gelatin they prevent it from setting?
We had to try it out, of course! So, read on to learn how to do this fruit enzymes gelatin experiment! You need gelatin, fruit, and several bowls.
You can use plain or flavored gelatin for this project. We made ours with plain gelatin. Choose the fruits you want to test.
We did ours with pineapple, orange, strawberry and kiwi. Then we left one without fruit as the control. Make the gelatin according to the package directions. Add the fruit into the different bowls. I made 5 separate ones using petri dishes. Divide the gelatin among the bowls.
Refrigerate for a few hours to set.
pineapple jello lab conclusion
Let your kids hypothesize. I knew for certain that fresh pineapple contained a specific enzyme that caused the gelatin to not set, so I used fresh pineapple. The other fruits I was not sure about and tried out a few that we had on hand.
Our strawberry and orange gelatins were solid and our pineapple and kiwi gelatins were still liquid. Bromelain is used as a meat tenderizer. Gelatin is made out of animal proteins. When you add water to the gelatin, long chains of protein form.
The protein chains collapse, making everything watery again. In the process of this experiment I did some studying and also learned that papaya, mango, guava, ginger, kiwi and figs also contain protein-digesting enzymes. They will also prevent gelatin from setting up. Our kiwi gelatin followed the same pattern as the pineapple and did not set up! Stop by her site to see what the other participating bloggers shared! Thank you for sharing this information. I am a science teacher for a non-profit ministry serving underprivileged youth in Camden, NJ.Please join StudyMode to read the full document.
In our hypothesis we predicted that the enzymes in the pineapple will denature when the temperature is changed. The prediction was partly correct.
Pineapples have special enzymes that denature gelatin molecules. Why our hypothesis was partly incorrect was lacked depth in that when changing the temperature by heating the pineapple to 40C it actually increased the speed and efficiency of the reaction taking place and increasing the amount of gelatin broken down by the enzymes in the pineapplebecause increasing the heat also increases the processes of an enzyme.
But once it hit a temperature high enough to completely alter the pineapple enzymes the results showed what we had predicted, the gelatin hardened because the pineapple's hydrogen bonds, that hold the enzyme together, broke and the enzyme unfolded, disrupting the overall structure of the protein.
The substrate could no longer bind to the enzyme's active site, and the enzyme could not catalyze the reaction. Fresh Raw Pineapple enzymes actively broke down the gelatins molecules throughout all of its trials. When it was heated to 40C it increased the reaction and helped break down the molecules, and at 75C some of the enzymes in the Also, through this experiment, students know some basic indexes to assess the efficiency of pumps used.
This is achieved by a rotor or impeller, which is driven by an external source of power to move a row of blades so as to There are not any real safety concerns for this lab other than making sure correct use and care of the microscope is used. Pseudostratified Ciliated Columnar Appears to have more than one layer of column of cells, but the cells appear to be resting on the basal lamina.
Cilia are on the top of the cells. Transitional Top cells appear to be larger, round, and have 2 nuclei. Connective tissue and a basement membrane Stratified Cuboidal online Double layer of squarelike cells, each having As we added more base, more HA is ionized and more salt formation occurs meaning the concentration of HA will decrease while the concentration of A- will increase.
The pH rises above the equivalence point because we are adding base to a solution with a relatively large volume. This means that all of the HA will be neutralized, causing the pH to change. Because of the rapid pH change around the equivalence point, the titrant has to be added in lesser and lesser amounts as we approach the equivalence point. As the titration progressed, we watched the graph on the computer and saw the pH increase and then rise very slowly.
This slow rise continued for a long period of time. After this portion of the graph, the pH increasedThey may have noticed a warning in the directions NOT to add fresh pineapple or kiwi to the mixture.
Doing so will cause the gelatin to remain in the liquid state, even after prolonged refrigeration. This is due to the presence of certain proteolytic enzymes in the fruit which digest or denature the protein molecules present in the gelatin.
Prepare gelatin in measuring cup using only half of the recommended boiling and cold water amounts given in the package directions. Stir well with spoon until all gelatin is dissolved. Place 3 ml of the designated fruit juice into each test tube. Failure to do so may result in mixing of juices and inaccurate results! Shake well to ensure proper mixing. Refrigerate test tubes overnight. On day 2, check the contents of each test tube for solidification of the contents.
Record the observations.
Jello Refraction Experiment
The solidified gelatin was not digested. Read the ingredients labels of the meat tenderizers. What enzymes do they contain? What is the enzyme source of each? Consider WHY these products are used to tenderize meat. Other than sanitary reasons, can you think of a second reason why pineapple processors are required to wear gloves and surgical masks?
This structure can be altered by heat, thus causing the enzyme to lose its normal function. In Lab II, students will test the effect of temperature on the ability of the proteolytic enzyme bromelein found in pineapple to digest gelatin. Knox gelatin, prepared according to procedure in LAB I.
Label the remaining tube as "RT" room temperature. Each group will design their own temperature gradient ranging from 0 C to C and will record the test tube numbers and corresponding test temperatures assigned for each.
Record the temperature of the room for test tube "RT. Heat or cool each test tube to the appropriate temperature as decided upon in Step 2. Leave test tube "RT" at room temperature. Hint: start with all tubes in cool water in the water bath, and gradually increase the temperature, withdrawing the numbered test tubes in order as the a appropriate temperature level in the bath is reached. Add 10 ml gelatin to each tube.
On day 2, check each test tube for liquidity of the contents.Please join StudyMode to read the full document. The Effect of Pineapple Juice on the Gelling Time of Gelatin Abstract: Fresh pineapple is known for not being able to gel and this experiment is aimed to figure out why.
Bromelain is an enzyme the breaks the chains in proteins making them inactive and pineapple are known for having it. In this experiment we tested other factors that pineapple contain to pin point what the culprit was.
Introduction: Why does canned pineapple make excellent jell-o but fresh pineapple falls short? A few hypotheses are that the fresh pineapple is too acidic, that Bromelain, an enzyme found in pineapple might break down the protein bonds of collagen, or there is a high concentration of fructose in the fresh pineapple. Our prediction was that if any one of these three were correct then the fresh pineapple would not gel. Below is an experiment that we did with fresh pineapple juice and canned pineapple juice; we tested each of them to see which gelled first.
We then tested each of our hypotheses above to see which property had a negative reaction to collagen. Method: To test our hypothesis first They speed up reactions by providing an alternative reaction pathway of lower activation energy. Like all catalysts, enzymes take part in the reaction - that is how they provide an alternative reaction pathway. But they do not undergo permanent changes and so remain unchanged at the end of the reaction. They can only alter the rate of reaction, not the position of the equilibrium.
Enzymes are usually highly selective, catalyzing specific reactions only. This specificity is due to the shapes of the enzyme molecules.pH and Enzyme Activity
Most of the pineapple consumed in the United States is canned in the form of juice as well as fruitbut fresh pineapple is much more flavorful, anddespite its tough bristly shell, is easy to prepare. The fruit probably first grew wild in parts of South America and then spread to the Caribbean, where Columbus encountered it. Byearly European explorers had carried pineapples as far as China and the Philippines. In the 18th century, pineapples were taken to the Hawaiian Islands, The name protein catalyst suggests that most enzymes are made of proteins.
A catalyst is a substance that speeds up chemical reactions without being consumed in the process. Giuseppe, Mp.I have just completed a two week drive around Iceland.
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Our trip was fantastic and Nordic Visitor made it so straightforward.Create and interpret histograms, bar charts, and frequency plots. Lesson 3 Central Tendency Compute and interpret the 3 measures of center for distributions: the mean, median, and mode. Lesson 4 Variability Quantify the spread of data using the range and standard deviation.
Identify outliers in data sets using the concept of the interquartile range. Lesson 5 Standardizing Convert distributions into the standard normal distribution using the Z-score. Compute proportions using standardized distributions.
Lesson 6 Normal Distribution Use normalized distributions to compute probabilities Use the Z-table to look up the proportions of observations above, below, or in between values Lesson 7 Sampling Distributions Apply the concepts of probability and normalization to sample data sets.
Prerequisites and Requirements This course assumes understanding of basic algebra and arithmetic. Why Take This Course This course will teach you the basic terms and concepts in statistics as well as guide you through introductory probability. Use statistical research methods. Compute and interpret values like: Mean, Median, Mode, Sample, Population, and Standard Deviation. Explore data through the use of bar graphs, histograms, box plots, and other common visualizations.
Investigate distributions and understand a distributions properties. Manipulate distributions to make probabilistic predictions on data. What do I get. ResourceTutoringStatistics Club at UCLA Close (X) PEOPLE Faculty ProfileFacultyStaffResearchersGraduate StudentsAlumni Close (X) COURSES Schedule of ClassesCourse Descriptions Close (X) Events SeminarsCommencement 2017ASA DataFestTM 2017 at UCLAStatistics Club at UCLA EventsDAE 2017 Conference Close (X) Our Master of Applied Statistics Program is linking with industrial, business, and government partners.
Engaged minds and thoughtful discussion at a seminar in April 2016. Members of the VCLA research group pose with Tony the robot. Click on the photo to see what Tony has learned to do. Pictured are the members of the JSB (Junction of Statistics and Biology) research group. JSB develops statistical and computational methods motivated by important questions in biomedical sciences and a plethora of genomic and health related data.
ASA DataFestTM 2017 at UCLA happened May 5 - 7. Students in competing teams from 7 universities analyzed a complex dataset for prizes, fame and glory.
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