Preview

Identifying Biological Macromolecules in Food Lab Essay Example

Powerful Essays
Open Document
Open Document
1105 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Identifying Biological Macromolecules in Food Lab Essay Example
Identifying Biological Macromolecules in Food Lab
Stefanie Bogaert

Observations

Part 1: Test for Proteins
Biuret Test for Protein
Test Tube Contents Colour Change Conclusions
1 Distilled water Clear to Blue tint There are no proteins present because there was no significant colour change
2 Albumin White translucent to Purple/violet Therefore there are proteins present because of the significant purple colour exposed from the reaction of the Biuret solution
3 Pepsin Brown to Pink/brown There is a little to none trace of proteins in the pepsin due to the slight pink colour created from the reaction with the Biuret solution
4 Starch Clear to Blue tint There is no proteins in the contents because there was no colour change revealing the presents of proteins

Part 2: Test for Starch
Iodine Test for Starch
Test Tube Contents Colour Change Conclusions
1 Starch suspension White (starch) and brown (iodine) > dark blue-black Therefore starch is present due to the change of colour in the solution
2 Distilled water Transparent (water) and brown (iodine) > translucent orange (diluted iodine) Therefore starch is not present due to the lack of reaction in the solution

Part 3: Tests for Sugars
Typical Reactions for Benedict’s Solution
Chemical Chemical Category Benedict’s Solution
(after heating)
Distilled water Inorganic Blue (no change)
Glucose Monosaccharide
(carbohydrate) Varies with concentration: very low: green low: yellow moderate: yellow-orange high: orange very high: orange-red
Maltose Disaccharide
(carbohydrate) Varies with concentration
(see results for glucose)
Starch Polysaccharide (carbohydrate) Blue (no change)

Benedict’s Test for Sugars
Test Tube Contents Colour Change Conclusions
1 Distilled water Remains translucent blue There is no sugar in the new solution
2 Glucose solution Grass green, solution becomes opaque This solution contains a high concentration of sugars, to the degree of no longer being translucent, but
Continue Reading
View Writing Issues

You May Also Find These Documents Helpful

  • Good Essays

    Erlenmeyer Synthesis
    • 998 Words
    • 4 Pages

    Erlenmeyer Synthesis

    In the second separation of this experiment, the Erlenmeyer flask with the first filtrate was put into a beaker so the filtrate was in the beaker. The beaker was then heated on a hotplate until near boiling. After the whey protein had precipitated, a vacuum filter was used to filter out the whey. These proteins were then air-dried. A qualitative test was done to indicate that the sample extracted was the protein whey. Again, a small test tube was used and 2 mL of protein test solution was put in the tube. Five drops of 10% NaOH and 2 drops of 0.5% CuSO4 were added to this tube. If a purple color showed, it would indicate there was protein in the test tube.…

    • 998 Words
    • 4 Pages
    Good Essays
    Read More
  • Satisfactory Essays

    Anatomy University Test
    • 259 Words
    • 2 Pages

    Anatomy University Test

    11. Was there any digested BAPNA containing the pepsin or deionizer (DI) water? How can you tell?…

    • 259 Words
    • 2 Pages
    Satisfactory Essays
    Read More
  • Good Essays

    Protein Modification Discussion
    • 468 Words
    • 2 Pages

    Protein Modification Discussion

    The graph was about turbidity reading at different temperatures at 340nm. The curve of egg white in the graph increased dramatically at first. At 80℃, the curve got a peak at 0.251. The peak was where the protein was fully denatured. Then, the curve dropped quickly. With the raising of the temperature, protein in the solution got denatured. When the temperature increased from 60℃ to 80℃, the structure of protein got unfold. When the solution was heated, the H-bond was broken. The hydrophobic parts of protein were inside the protein surrounded by hydrophilic parts before unfolding. With the temperature increasing, the hydrophobic parts were exposed. The hydrophobic parts of proteins interacted. The reason why the turbidity reading got bigger is that protein unfold and the unfold proteins got coagulation. The coagulation caused the turbidity of solution increasing. The melting temperature of the native egg white sample was at the half of denaturation. It is about 71℃. The curve dropped because coagulation floated to the surface of solution. The curve of succinylated egg white did not change much. The –NH3+ of protein in egg white was replaced by COO- at pH8, so the protein was negative charged. The fastest coagulation of protein is at pI (isoelectric point). Because the pH of solution was at pI, the whole process is slow.…

    • 468 Words
    • 2 Pages
    Good Essays
    Read More
  • Good Essays

    Biochemistry Output
    • 258 Words
    • 2 Pages

    Biochemistry Output

    A positive Biuret test indicates the presence of proteins in the filtrate. Biuret is used to test for proteins. It is a light blue color and changes to purple in the presence of protein, a polymer made of amino acids. It will not change color when only amino acids are present.…

    • 258 Words
    • 2 Pages
    Good Essays
    Read More
  • Satisfactory Essays

    physioex post lab questions
    • 371 Words
    • 2 Pages

    physioex post lab questions

    Exercise 8: Chemical and Physical Processes of Digestion: Activity 3: Assessing Pepsin Digestion of Protein Lab Report…

    • 371 Words
    • 2 Pages
    Satisfactory Essays
    Read More
  • Good Essays

    Protein and Initial Chemical Test
    • 588 Words
    • 3 Pages

    Protein and Initial Chemical Test

    Biuret reagent will turn your skin a brownish-purple because Iodine detects protein in a substance by changing the color to a brown or purple shade, and since your skin contains protein it will also change color.…

    • 588 Words
    • 3 Pages
    Good Essays
    Read More
  • Good Essays

    Techniques and Methodologies for Extracting Proteins and Purifying Enzyme X
    • 575 Words
    • 2 Pages

    Techniques and Methodologies for Extracting Proteins and Purifying Enzyme X

    The blue-green tinted proteins in Enzyme X give a distinct color to algae. The proteins are contained in the cells, so the cells need to be lysed (disintegration of the cell wall or membrane.) Substance X contains Enzyme X. As a note, the compound needs to be perfectly pure before studying or it will not produce wanted results.…

    • 575 Words
    • 2 Pages
    Good Essays
    Read More
  • Powerful Essays

    Molecules
    • 1089 Words
    • 7 Pages

    Molecules

    Our results are correct because water and starch should not contain protein (starch is a polysaccharide but not of an amino acid) and therefore remained blue unlike Albumin and Pepsin which do contain proteins causing them to turn into a different color.…

    • 1089 Words
    • 7 Pages
    Powerful Essays
    Read More
  • Good Essays

    The Four Basic Food Molecules
    • 989 Words
    • 4 Pages

    The Four Basic Food Molecules

    A molecule is a group of atoms bonded together that represent the smallest unit of a chemical compound that can take part in a chemical reaction. (http://www.dictionary.com) In kitchen chemistry today, there are many types of food molecules such as minerals, vitamins, fiber, and water. But there are four molecules that people refer to as food, also known as the four basic food molecules, which can be used to produce energy which are carbohydrates, lipids, proteins, and alcohol which is not considered a basic nutritional component of food.…

    • 989 Words
    • 4 Pages
    Good Essays
    Read More
  • Satisfactory Essays

    Chemistry Lab Questions
    • 941 Words
    • 4 Pages

    Chemistry Lab Questions

    5. List whether each of the following substances was positive or negative for protein, as indicated by the Biuret test. (7 points)…

    • 941 Words
    • 4 Pages
    Satisfactory Essays
    Read More
  • Better Essays

    Chemistry Lab Report for Vitamin C Estimation by Back(Idiometric) Titration
    • 3317 Words
    • 14 Pages

    Chemistry Lab Report for Vitamin C Estimation by Back(Idiometric) Titration

    Colour change after adding indicator (starch) to the solution is blue (dark brown colour appears…

    • 3317 Words
    • 14 Pages
    Better Essays
    Read More
  • Satisfactory Essays

    Assignment: Science Nutrition
    • 450 Words
    • 2 Pages

    Assignment: Science Nutrition

    1. Given MRS GREN is an acronym for features of a living thing. Define Nutrition in our context study.…

    • 450 Words
    • 2 Pages
    Satisfactory Essays
    Read More
  • Satisfactory Essays

    Easy Notes
    • 418 Words
    • 2 Pages

    Easy Notes

    Solutions and Color Reactions for “Benedict’s Test for Reducing Sugars” and “Iodine Test for Starch.”…

    • 418 Words
    • 2 Pages
    Satisfactory Essays
    Read More
  • Good Essays

    Bio practical
    • 706 Words
    • 4 Pages

    Bio practical

    Benedicts test: Blue colour remained the same. Abundant amount of blue solutions remained the same and it was opaque.…

    • 706 Words
    • 4 Pages
    Good Essays
    Read More
  • Satisfactory Essays

    Experiment: To Test Food to See if They Contain Starch
    • 252 Words
    • 2 Pages

    Experiment: To Test Food to See if They Contain Starch

    1) Two to three drops of the iodine were dropped in the potassium iodine solution to 2cm cube of the starch suspension.…

    • 252 Words
    • 2 Pages
    Satisfactory Essays
    Read More