Carbohydrates, Proteins, lipids, and nucleic Acid Lab Exercise 6 Date: 9/17/12 Bio 102-11 Purpose the purpose of this experiment was to perform test to detect the presence of carbohydrates, proteins, lipids, and nucleic acids. Explain the importance of a positive and a negative control in biochemical test. Use biochemical test to identify an unknown compound. Background Most organic compounds in living organisms are carbohydrates, proteins, lipids, and nucleic acids they are called macromolecules. Each of these macromolecules is made of smaller subunits. These subunits are linked by dehydration synthesis. Dehydration synthesis is an energy requiring process in which a molecule of water is removing and the two subunits are boded …show more content…
Table 6.1 Solutions and color reaction for Benedict’s test for reducing sugars and 2 iodine test for starch | tube | solution | Benedict’s color reaction | Iodine Color Reaction | 1 | 10 drops onion juice | greenish | Brent orange | 2 | 10 drops potato juice | yellow | brown | 3 | 10 drops sucrose solution | Light blue | Dark brown | 4 | 10 drops glucose solution | Bright orange | No change | 5 | 10 drops distilled water | Light blue | No change | 6 | 10 drops reducing sugar solution | Light orange | No change | 7 | 10 drops starch solution | Light blue | black | (6.2)Material and Methods in the process or exercise of measuring the starch we were used the following material and how we used them to conduct the experiment. Obtain seven tubes the material to be tested table 6.1 and then add seven to ten drops of iodine to each tube, and then record the color of the tubes contents in table 6.1 Starch or amylum is a carbohydrate consisting of a large number of glucose units joined by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store. It is the most common carbohydrate in the human diet and is contained in large amounts in such staple foods as potatoes, wheat, maize (corn), rice, and cassava. Picture of starch molecules Table 6.1 tube | solution | Benedict’s color reaction | Iodine Color Reaction | 1 | 10 drops onion juice | greenish | Brent orange | 2 | 10 drops potato juice | yellow |
4. There are other types of reagents used to determine what type of biomolecule a substance is. For example, copper ions present in Benedict’s reagent reacts with the free end of any reducing sugars, such as glucose, when heated. Originally blue in color, these copper ions are reduced by the sugar, and produce an orange-red colored precipitate. Alternatively, iodine-potassium iodide (IKI) may also be used when working with starch. IKI contains special tri-iodine ions which interact with the coiled structure of a starch
Atoms are the basic units of matter and all life is based on them. Life on earth is based on the element carbon. It is a highly versatile atom able to form four covalent bonds with itself or other atoms such as hydrogen and water. Atoms combine to form molecules and those that are carbon based are referred to as organic molecules. Organic molecules occur in four different types in living cells; carbohydrates, lipids, proteins and nucleic acids. They are also known as hydrocarbons due to the presence of both hydrogen and carbon. Carbohydrates are made up of carbon, hydrogen and oxygen in the ratio 1:2:1. They are important sources of energy and are classified in three main groups; monosaccharides, disaccharides and polysaccharides.
The purpose of this lab was to test different substances using various procedures to see what biomolecules were present and ultimately find out what restaurant Anna Lyza had eaten at before she died. For the first control test, we used vegetable oil to test for lipids. So, if the solution does not contain lipids, it does not become translucent when placed onto a paper bag square and held up to a light. So, it is a negative result. However, in the presence of lipids, the solution will become translucent when placed onto a paper bag square and held up to a light. Therefore in this case, the result is positive. On the other hand, we used albumin egg to test for proteins in another control test. If the solution does not contain proteins, it will not experience any color change and so it is a negative result. When there are proteins existing in the solution, it will turn bluish/purplish and for this reason it is a positive result. Furthermore in the third control test, we used dextrose to test for simple carbohydrates such as glucose. If the solution does not contain simple carbohydrates, it will not undergo any color change and will remain a blue color. So, it is a negative result in this circumstance. If there are simple carbohydrates present in the solution, the solution will turn reddish and so the result is positive. For the last control test, we used starch solution to test
The most common macromolecules found in living organisms are lipids, carbohydrates, proteins and nucleic acids. Briefly, the meaning of macromolecules is that they normally contain two or more molecules in them and their main functions are to store energy, information and much more. Most foods are known to be combinations of macromolecules. While some of these compounds can be detected by taste tests, many cannot. Scientists then use certain tests to determine the presence of macromolecules.
A cell, the building block of all living organisms, is composed of four fundamental biomolecules: proteins, carbohydrates, sugars and lipids. Proteins provide a vast amount of functions cells such as they serve as enzymes, provide structural support to cells, and act as antibodies. Reagents are used to spark a chemical reaction. The reagent used to detect protein traces in a substance is Biuret’s. Biuret’s will turn purple if proteins are present and blue if they are none. Biuret’s copper particles, have a charge of +2, are diminished to a charge of +1 when peptide bonds, which are in proteins, are present, creating the color change. Polysaccharides, which are carbohydrates, are most notably known to provide energy to the body, but they also help in breaking down fatty acids. Iodine is the reagent used to determine whether a substance has starch in it. The iodine/starch complex has energy levels that are only for retaining unmistakable light, giving the complex its extraordinarily dark black-blue shade. If there is no starch found, iodine will remain its natural yellowish-brownish color, but if starch is present, iodine will turn blue-black. Monosaccharides, which are sugars, like polysaccharides, provide the body with energy. To detect monosaccharides, the reagent, Benedict’s, is used. Benedict’s reagent is added to a test tube, then it is placed in
3. State the name and structure of the functional group for each type of biologically
2. Four unknown samples were included in the lab kit: flax seed meal, potato starch, egg whites, and dried milk. Using the results of the biochemical testing, determine which number corresponds to the correct unknown. (8 points)
b) Benedict test the solution color will change from blue to pink/orange red, indicating simple sugars are present. Lugols test the solution color will change from yellowish brown to dark purple, indicating starch and polysaccharides are present. Sudan iV test the lipid content will turn into red, indicating lipids are
2.List whether each of the following substances was positive or negative for reducing sugar, as indicated by the Benedict's test. (6 points)
Dehydration-synthesis is a reaction that occurs to form different types of macromolecules. It is a reaction that leaves a macromolecule structure along the lines of developing its own specific function in a living organism. The 4 most common ones are carbohydrates which includes monosaccharides and polysaccharides, lipids, proteins and nucleic acids (Mack 2012). Scientists identify different types of macromolecules to achieve a better understanding on how they function in our bodies. This can be achieved by studying their chemical properties and structure.
enzymes that will be used during this lab to test the ability of amylase to break down starch ,a
This experiment consisted of setting up a control group of starch in various temperature and then placing both fungal amylases and bacterial amylases in a mixture of starch and placing the solution of amylase and starch in various temperatures of water. After a certain amount of time- different amount of time needs to be used in order to have reliable results- iodine is added in a well on spot plates, then two drops of the mixture of amylase-starch is added from each temperature used, by adding iodine into the plates the mixture will show how much starch was hydrolyzed, this is used to calculate the amount of
For this experiment, we have to prepare our phosphorylase which extracted from a potato. We prepared by weighed about 250 grams of peeled potato and cut it into cubes. The extracts then blended with 100mL of 0.1M NaF. After filtered the contents into a clean 250mL centrifuge bottle, we centrifuged it for 3 minutes. Then, separated the supernatant into a centrifuge bottle, which is our phosphorylase preparation. The enzyme assay used in this experiment today is the iodine test. As the iodine reacts with starch, it will form a brown, blue or black precipitate due to the iodine ions forcing into a linear arrangement. The endpoint of the enzyme reaction indicates the presence of starch by using the iodine test to determine. The faster the endpoint is reached, the less active the phosphorylase is.
There are four types of biomolecules, carbohydrates, lipids, proteins, and nucleic acids. Carbohydrates are large chains of sugar found in food and living tissues. This includes sugars, starch, and cellulose. They have the same ratio of hydrogen and oxygen that water has, 2:1. They are broken down to release energy in the animal body. Lipids are any organic compounds that are fatty acids and don’t dissolve in water but do in organic solvents. Fatty acids can be found in natural oils, waxes, and steroids. Proteins are macromolecules that do everything in the cell. They are tools and machines that make things happen. Nucleic acids are long strands of nucleotides, and function primarily in storage and transmission of genetic information. There are two types of nucleic acids, DNA and RNA. DNA is the genetic material of all cellular organisms, and RNA sends out messages from the information that is held in the DNA.
3 drops of Lugol’s solution is added to each tube. Presence of starch is indicated by dark purple color occurrences. The amount of starch is indicated by the shades of reddish brown.