Introduction Carbohydrates are biomolecules that consist of a chain or ring of carbon atoms attached to hydrogen and oxygen atoms. The simplest formula for carbohydrates is (CH2O)n. Carbohydrates are important to organisms for a variety of reasons. They are used to form the structural components of the cell, aid in energy storage, and serve as intermediary compounds for more complex molecules. Carbohydrates are classified as either monosaccharides, disaccharides, or polysaccharides. Both monosaccharides and disaccharides dissolve easily in water. Carbohydrates are produced in plants through the process of photosynthesis and animals obtain these carbohydrates by eating the plants. ("BIO 1510 Laboratory Manual," 2016) Monosaccharides are known …show more content…
Starch, cellulose, glycogen, and chitin are all examples of polysaccharides. According to the BIO 1510 Lab Manual (2016) polysaccharides are not very soluble in water but can be made to go into solution through heating or agitation. Polysaccharides are excellent energy storage molecules because they are easily built and broken down by enzymes. Forming fairly compact structures, polysaccharides allow energy storage without the space required by a pool of free glucose monomers. Other polysaccharides form strong fibers that provide protection and structural support in both plants and animals. (Carbohydrates.” Home, …show more content…
First is the Benedict’s test for reducing sugars which determines if a carbohydrate contains a free aldehyde or ketone group. When Benedict’s reagent is heated with a reactive sugar the color of the reagent changes. The initial solution color of the Benedict’s regent is sky blue. Depending on the number of available sites for the reaction to occur, the reaction will result in a solution that may range from green to yellow to orange to brick red, a red precipitate may form if more time is allowed. The test will only show a positive reaction for starch if the starch has been broken down to maltose of glucose. ("BIO 1510 Laboratory Manual," 2016)
The Barfoed’s test for monosaccharides is used to differentiate between monosaccharides, disaccharides, and polysaccharides. Because of the acidity of the solution, only monosaccharides are able to reduce the copper ions. The solution will go from a sky blue to a red precipitate when there is a positive reaction for a monosaccharide. ("BIO 1510 Laboratory Manual,"
Data from Table 1. confirms the theory that as the concentration of glucose increases so will the absorbance of the solution when examined with the glucose oxidase/horseradish peroxidase assay. Glucose within the context of this assay is determined by the amount of ferricyanide, determined by absornace, which is produced in a one to one ratio.1 Furthermore when examining the glucose standards, a linear calibration curve was able to be produced (shown as Figure 1). Noted the R2 value of the y = 1.808x - 0.0125 trend line is 0.9958, which is statistically considered linear. From this calibration curve the absorbance values of unknowns samples can be compared, and the correlated glucose concentration can then be approximated.
The unknown substance is probably a carbohydrate because it tested positive for starch which is a polysaccharide. This reaction also had very similar results as the Lugol’s test for potatoes which is a polysaccharide. Although the colors from the test for potatoes were not the same colors as the test for the unknown; the Biuret test had a slight color change and the Lugol’s test had a dramatic color change for both the unknown and potatoes. I am sure that the unknown was a starch, but the Benedict’s test for sugar was positive for the potatoes while the Benedict’s test for the unknown didn’t have a color change. The unknown probably did not have a color change for the Benedict’s test simply because there were not enough sugar present in the unknown for it to test positive. The Sudan IV Test for Lipids did not test positive for the unknown nor the potatoes because there isn’t a trace of lipids in starch. Based on my results, the unknown has a little protein, a lot of starch and no traces of lipids or
The methyl red (MR) test and the Vogues-Proskauer (VP) test. The MR test is used to reveal whether the E. coli or S. epidermidis produced high levels of acid during the glucose fermentation. When the high levels of acid are present it will turn the organism red. If it is low, it will remain yellow. It this experiment, both cultures turned red. The VP portion of the experiment is to identify acetoin. Next, drops of Barritt’s Reagent A and Barritt’s Reagent B are added to the E. coli and the S. epidermidis vials. Then, allow the vials to sit undisturbed for 30 minutes. A positive result can be observed in both vials which is a formation of a thin red surface layer. Concluding that the E. coli and S. epidermidis are competent enough to execute a mixed acid
This lab used many test to determine which functional groups were present in certain substance. The Benedicts test was used to identify reducing sugars (glucose and fructose) based on their ability to reuce the Capric ions to cuprous oxide at high pH. The Cuprous oxide is reddish orange in color when shown to be at high levels by the test, and greenish when at low levels. In both the onion juice and glucose solution the reducing sugar levels were very high, because the test came back dark orange. The starch solution had relatively low levels of reducing sugar present and this was seen by the test coming back cloundy blue, green and brown.
The independent variable for this experiment is the enzyme concentration, and the range chosen is from 1% to 5% with the measurements of 1, 2, 4, and 5%. The dependant variable to be measured is the absorbance of the absorbance of the solution within a colorimeter, Equipments: Iodine solution: used to test for present of starch - Amylase solution - 1% starch solution - 1 pipette - 3 syringes - 8 test tubes – Stop clock - Water bath at 37oc - Distilled water- colorimeter Method: = == ==
The Structure and Function of Carbohydrates Large biological molecules are called macromolecules, there are giant molecules (polymers) made up of repeating units (monomers). Carbohydrates are one of the main classes of biological molecules. Macromolecule units (monomers) are joined together by condensation reactions and hydrolysis reactions split macromolecules down into their individual units. Carbohydrates are molecules that contain elements of carbon, hydrogen, and oxygen. Carbohydrates have a 2:1 hydrogen to oxygen ratio, there are twice as many hydrogen atoms as oxygen atoms (the same proportion as in water).
The observed results matched the general expected results of Galactose. Music acid formed a white precipitate. Bial's and Benedicts test had red precipitate. Seliwanoff test had no color. Bial's test had a dark brown color. Looking into the results obtained by doing the test Galactose was the adequate choice to what my unknown was.
Another chemical property that is important is that saliva is an enzyme amylase that helps breakdown starch into sugars. Starch plus water with amylase goes into maltose. During digestion the glands secrete enzymes and hydrochloric acid. This is why hydrochloric acid is used to lower the pH level. Pepsin catalyzed the reduction of proteins into polypeptides and amino acids. A temperature of approx. 37 degrees is required. Hydrochloric acid is what gives a lower pH and this kills any harmful microorganisms that may be present in the food being digested. Pancreation has an amylase just like saliva does. This is why it was used in part five of the lab to break down starch. It is just like saliva and breaks starch down into the component sugar. Our bodies cannot absorb any protein, starch or fats if they are not broken down into their component. Another chemical property is that starch is identified by using iodine-potassium iodide. The iodine changed from yellow to blue or black when starch is present. This is because the iodine binds to the starch molecules. Biuret reagent was used to be able to distinguish between proteins and polypeptides and amino acids. The reagent will turn purple when a protein is
We were able to verify the statement by finding which macromolecules were present in the stomach contents. If he was telling the truth, the stomach contents would have protein and starches in them because the egg whites and pancake mix both consist of those macromolecules respectively. To figure out the results, a series of tests were used including different reagents and indicators. For the monosaccharides test, Benedict’s reagent was used to identify when the reaction between the sugars and solution took place. The changes in colour from blue to orange-brown indicated the various approximate sugar concentrations from 0% to more than 2%. For the starch test, Lugol’s solution which is made of iodine was used to react with the starches. In the presence of starch molecules, the solution turned blue-black. In order to test for lipids, two tests were used; the first involved Sudan IV solution which can indicate lipids that are soluble in non-polar solvents. The second was a translucence test, if lipids were present in the contents, the paper would allow the light through – be translucent. Lastly, for the protein testing, Biruet reagent’s test reacting with the peptide bond allowed the proteins to be tested producing colour changes from blue to darker purple to indicate the levels of protein
What are carbohydrates? What role do they play in our bodies? The role of carbohydrates in our bodies is to provide energy, as they are the body’s main source of fuel. These biochemicals are needed for physical activity, brain function and to operate the organs. Carbohydrates can be found in dairy, fruits, grains, and in starchy vegetables. Complex carbohydrates are foods which contain vitamins, minerals, and antioxidants. Oat meal, brown rice, quinoa, potatoes, beans, peas, whole grains and other starchy vegetables are good examples of complex carbohydrates. Simple carbohydrates are a major source of energy for the body and can be found in fruits, fruit juices, and dairy products. While both kinds of carbohydrates use glucose as a source,
They do indeed have other macromolecules but at a low concentration that would make it difficult to test for. This can be tested the same way, following the same procedure of the Glucose test. They would have the same characteristics of the Unknown #2 solution since they both have high levels of detectable glucose. It would also have a similar range of 2.6-3.5% sugars within the solution since the test would give a similar colour change. Errors that could have altered the accuracy of this experiment would be the temperature of the water. To ensure a proper reaction and colour change to occur the water strictly has to be at 80°C. If the temperature is too high/low it could alter the reaction and give inaccurate results. To ensure that this error does not affect the accuracy the temperature can be consistently monitored to stay consistent at 80°C. Monitoring the hotplate setting could also be beneficial to make sure the temperature does not exceed the ideal temperature range causing altercations in the
Carbohydrates (also known as carbs and sugars) are simple organic molecules whose basic role in the body is to provide energy, because they represent the easiest and fastest way to get the required energy. The combustion of 1 g of these compounds releases 4.1 calories.
There are many things which make humans up. And there are also many things that we cannot live without. Some people may not be able to live without their cell phones or without the internet in today’s society. Although we continue to act as if material things are the most important things to us, I believe what is most important is what we cannot actually live without and those things are simply carbon dioxide and oxygen. Although we cannot live without those elements, us humans need food to keeps us fueled throughout our daily lives. Carbohydrates and starches are one of the three basic things which keeps our body fueled, good carbohydrates keep us fueled with good energy, however; bad carbohydrates keep us fueled with bad energy for a short
To obtain a positive result the starch must be heated with addition of a dilute hydrochloric acid (this process is called hydrolysis) breaking the glycosidic bond with acidic and heated conditions. This process renders the starch different than its original form, but it allows for the breakdown of the monosaccharaides (making up the starch) into aldehydes and alpha-hydroxy-ketones. These then react with Benedict’s reagent providing a positive result to the
Complexity of compounds is the reason they must be absorbed long before the physical activity. Starch a main area of complex carbohydrates. It has several bonds. Starches are tightly bound carbon molecules and have several attaching elements. This bonding complexity is the reason starches are capable of retaining large amounts of energy. These compounds should be taken into an athlete's body prior to intense physical activity because an energy storage supply is necessary when simple compounds are completely oxidized.