Introduction The purpose of this lab is to use control variables to help identify different macromolecules. Biological systems are made up of these four major macromolecules: carbohydrates, lipids, proteins and nucleic acids. Carbohydrates are sugar molecules (monosaccharides, disaccharides, and polysaccharides) which make them the most abundant macromolecule on the earth. Lipids (oils and fats, phospholipids and steroids) are insoluble in water and perform many functions such as energy source, essential nutrients, hormones and insulators (Lehman, 1955). Proteins are made up of peptide bonds holding amino acids together to perform biological functions like enzymes, antibodies, for transport and structure (Asmus, 2007). Lastly, nucleic acids …show more content…
The iodine test determines the presence of starch in biological materials. It is predicted that, if starch is not present, the solution with iodine remains yellow. However, if starch is present the solution with iodine becomes a blue-black colour. Plants have starch as the storage polysaccharide (glucose units held together by glycosidic bonds) while animals have the equivalent of glycogen. In this experiment, the dark blue colour is visible because of the helical amylose and amylopectin reacting with iodine (Travers et al., 2002). The starch-iodide complex forms because of the transfer of charge between the starch and iodide ion and results in spacing between the energy levels. This allows the complex to absorb light at different wavelengths resulting in a dark blue colour (Travers et al., 2002). A blue colour would indicate a positive test while a yellow colour would show a negative test. The Benedict’s test is useful for reducing sugars. Reducing sugars are a carbohydrate that can either be straight chains with an aldehyde group at the end or as ring forms with a ketone group (Hill, 1982). Monosaccharides and most disaccharides will reduce copper (II) sulfate. The Benedict’s solution contains cupric ions and the aldehyde groups at the end of the sugars will reduce the cupric ions to cuprous ions (Cu+). There will be a precipitate of copper (I) oxide when the cuprous ions combine with oxygen (Hill, …show more content…
1% glucose, 1% maltose and 1% lactose all progressively get positive results by changing colours to reddish brown at the end of this experiment. In this case the aldehyde functional group that is present in the products (monosaccharides and some disaccharides) in this reaction is able to reduce copper in the presence of alkali and this produces colour changes while converting to an aldose sugar. Honey is made of fructose and glucose which instantly turned brown after the test-tube was placed in the boiling water because of its active aldehyde and carbonyl group. The copper (II) sulphate present in the Benedict’s solution reacts with electrons from the aldehyde group which results in a redox reaction to from cuprous oxide, a red brown precipitate that seen in all of the above mentioned solutions (Hill, 1982). Beer also gave positive results because it contains aldehydes and ketones (i.e. acetone, trans-2-butenal, furfual) during its beer production process where the sugars are converted through fermentation (Hill, 1982). As a result, beer attained a positive result. Starch and glycogen produced a negative result because they are polysaccharides and don’t have the aldehyde functional group. Distilled water contains no monosaccharides and has to ability to reduce the copper ions (Cu+) and
Fermentation test is used to determine if unknown #398 uses any oxygen to ferment carbohydrates and acids. Oxidation tests were used to determine if unknown #398 metabolizes carbohydrates and acids by cellular respiration. Both tests are observed by inoculation of unknown #398 into 3 sugar broths: lactose, glucose, and mannitol and 1 citrate (Citric acid) slant. Fifth test, Hydrolytic and Degradative reactions is used to determine if unknown #398 contains enzyme, amylase that hydrolyzes starch after streaking on a starch plate. Next test, inoculation of a urea broth and is used to determine if unknown #398 contains urease that hydrolyzes urea.
For instance, we could not conclude that mitochondrial activity is present in Supernatant II. However, our experiment showed that the boiled corn kernels did not undergo any mitochondrial activity while the raw corn kernels did. This might indicate that raising the temperature might have an effect on the function of dehydrogenase. Moreover, our found that starch granules are present in both sediment I and the “gunk”. Indeed, some parts of this experiment were not successful because the procedure was not followed
All enzymes are under the class of protein biomolecule. Amino acids are the basic units that are combined to make up an enzyme. The biomolecule that stores information is a Nucleic Acid. The specific 3-D region within an enzyme is called the active site. The chemical
Starch solution is then placed into the test tube at a quantity of 5 mL. 5 drops of Lugol’s Iodine solution is added to the test tube. If the color changes, then it is known that starches are present in the solution. Proteins are next tested. In order to do this, 5 mL of gelatin solution is added to the test tube. 10 drops of Biuret’s reagent are added to test for protein.
The investigation was carried out to identify the presence or absence of biological molecules in serum 2216. If the concentration in each test tube of the dilutions carried out will be more concentrated then the concentration of the test tube before it, then the color will be at an equal concentration with the other dilutions performed. The hypothesis was wrong because of the difference in concentrations due to the different measurements within the dilutions done. The test for starch was to add a drop of iodine solution to the pipette in the spotting tile. A reducing sugar solutions is add inside a test tube with 3 drops to then add 3 drops of benedicts and plane in a water bath.
Sucrase activity increases with increasing sucrose concentration Materials and Methods Effect of pH on Enzyme Activity 1. Dependent Variable amount of product (glucose and fructose) produced 2. Independent Variable pH 3. Controlled Variables temperature, amount of substrate (sucrose) present, sucrase + sucrose incubation time Effect of Temperature on Enzyme Activity 1.
Proteins were found in the victim’s stomach contents by exposing the contents to the Biuret solution and getting a positive result after the solution became purple. Protein can also be found in the meat of the victims typical, “…pizza with sausage, pepperoni, and bacon…”. Lastly, starches were found in the victim’s stomach contents though exposing the victim’s stomach contents to the Iodine solution and getting a positive result after the solution became a dark color. In pizza, starches can be found in the entire
Title: How Ph Levels Affected the Fermentation of Beer Hypothesis: The beer will be left with more sugar deposit as the Ph levels increase because alpha/beta -amylase will no longer function. Predictions: Alcohol Percentage Analysis for the Control and the Experimental During this experiment, the pH level was increased, therefore Alpha-Amylase was favored. Due to the nature of Alpha-Amylase cutting randomly through a large carbohydrate molecule, it leaves bigger sugars in the flask, which cannot be digested by yeast. Due to this, less reactions should occur in the experimental, therefore leading to a lower percentage of alcohol production, compared to the control.
B-galactosidase breaks down the disaccharide lactose into simple sugars glucose and galactose. However, glucose is a colorless compound hence it has to be substituted with a compound that is detectable by a visible color change. Hence,
The effects of alcohol on Biological Membranes. Introduction In this experiment it will be analysed the damage alcohols can have on biological membranes. Membranes are made up of lipids and proteins. Membranes usually help maintain the balance in a cell as it holds all the cellular materials.
5 water bath were set up each to10 °C. (5 were used do the experiment faster) 5 cm3 of starch solution were added into the 5 test tubes that were labeled test tubes. Then 5 cm3 of amylase enzyme was added into the other 5 test tubes that were labeled. Put one of the starch solution test tube (preferably the one labeled 1) and one of the test tube containing amylase into the water bath (10 °C).
A 50 mL buret was obtained and was washed with NaOH solution. After filling the buret with NaOH (titrant) and preparing the KHP (analyte) in the Erlenmeyer flask, the solutions were titrated. The volume used from the NaOH solution was recorded. C. Determination of the Acidity of Soft Drinks First, the soft drinks were heated.
In order to utilize casein, bacteria cells secrete proteolytic exoenzymes (amylases, proteases, pectinases, lipases, xylanases and cellulases) outside of the cell that hydrolyze the protein to amino acids. The amino acids can then be used by cells after crossing the cell membrane via transport proteins [169]. Starch hydrolysis test is used to differentiate bacteria based on their ability to hydrolyze starch with the enzyme α-amylase or oligo-l, 6-glucosidase. These enzymes hydrolyze starch by breaking the glycosidic linkages between the sugar subunits. It aids in the differentiation of species from the genera Corynebacterium, Clostridium, Bacillus, Bacteroides, Fusobacterium and members of Enterococcus [170].
The experiment shall use several concentrations of sucrose solution and a substance known as Methylene blue. A piece of potato/ carrot shall be placed in a boiling tube and the solution shall be poured into it. This tube shall have Methylene blue added into it. After incubation some of this solution shall be taken out with a pipette and inserted into a separate boiling tube containing the same sucrose solution however this solution shall be known as the pre-incubated solution. The drop shall be watched so as to see if the density of the water and concentration of sucrose has increased or not, displaying the water
If the broth turned a reddish color, the result was then positive. If there was no color change, then a small amount of zinc powder was added. If there was no color change, the result was also positive, but if there was a red coloration development after the zinc was added, the result was then negative. Both Unknown bacteria (16A and 16B) were positive for nitrate reduction. The tubes were then