Biology: Chemical Tests and Test

And finally into test tube 3, I pipetted 1.0 ml turnip extract and 4.0 ml of water. The contents of test tube 1 was poured into a spectrometer tube and labeled it “B” for blank. “B” tube was now inserted it into the spectrometer. An adjustment to the control knob was made to zero the absorbance reading on the spectrometer since one cannot continue the experiment if the spectrometer is not zeroed. A combination of two people and a stop watch was now needed to not only record the time of the reaction, but to mix the reagents in a precise and accurate manner. As my partner recorded the time, I quickly poured tube 3 into tube 2. I then poured tube 2 into the experiment spectrometer tube labeled “E” and inserted it into the spectrometer. A partner then recorded the absorbance reading for every 20 seconds for a total of 120 seconds. After the experiment, a brown color in the tube should be observed to indicate the reaction was carried out. Using sterile techniques, any excess liquid left was disposed

If feeding efficiency and reproduction have a direct correlation, and a population started with equal proportions of individuals with each of three feeding types, metal spoon, metal knife, and plastic fork, the frequency of the population with metal spoons as their feeding structure will increase in the next generation. While the frequency of metal knifes and plastic forks will decrease. Furthermore, since the organisms with the metal spoon feeding structure have a higher fitness level, this population will evolve by natural selection to a point where the metal spoon phenotype will be in abundant. While the organisms with metal knifes and plastic forks phenotypes will decrease in frequency due to the lack of reproduction. Eventually, if this population persist overtime, most of the organisms, if not all, will have the metal spoon phenotype, while very few, if not any, will have the metal knife or the plastic fork phenotype.

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

All living things contain some form of organic macromolecules including: Lipids, proteins, carbohydrates and nucleic acids. All of these organic molecules are alike in the sense that is they are made up of bonded elements such as carbon, hydrogen, oxygen, and to smaller quantities nitrogen, phosphorus and sulfur. The macromolecules each contain large long chains of carbon and hydrogen atoms and often consists of repeating smaller molecules bonded together in a repeating pattern (polymers). To test whether a specific solid white substance is a protein is simple due to the unique chains found in the respective type of macromolecule. To test if the substance is a carbohydrate, two tests could be performed on separate samples of the object. First,

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

The purpose of this experiment was to find out the nutrient content of unidentified food samples and to use chemical reagents to see if the unidentified foods for sugar, starch, protein and fat (lipid) content. After comparing the color changes in each unknown substance then you will be able to see the amount of sugar, starch, protein or fat there is in the unknown substance.

3. State the name and structure of the functional group for each type of biologically

Analysis: In this experiment, every substance tested positive for at least 1 organic compound. Corn oil tested positive for lipids. Honey and oats tested positive for starch. Honey, apple juice, and unknown 1 tested positive for sugar. Egg white, gelatin, and unknown 2 all tested positive for proteins. So, not a single substance didn't test positive for at least 1 organic compound. All the indicators used in this experiment change color when in the presence of a compound; therefore, they chemically react with the compound. No errors were made during this experiment

The purpose of this experiment is to exemplify how differences in molecular weight allow separation of polymers from their monomers. Methods of dialysis and gel filtration chromatography will be used to separate a glucose monomer from a starch polymer. Colorimetric glucose oxidase assay will be used to monitor the presence of glucose and a colorimetric iodine assay will be used to monitor the presence of starch in prepared solutions after separation

Carbohydrates are macromolecules which and contains carbon, hydrogen and oxygen (C,H,O). There are also two types of sugars, sweet soluble and starches which are non-soluble. Sugars can also be single or simple sugars.Carbohydrates can be found in a wide variety of foods such as pasta, wheat and grains, rice, potatoes, fruits and sugars. Carbohydrates are broken down into

A macromolecule can be any of a general selection of molecules, such as: proteins, carbohydrates, lipids, and

The aim of this experiment is to observe and record the rate of the blue water in the dialysis tube diffusing into the beaker containing different concentrations of salt over 20 minutes to see what effect the concentrations of salt has on the rate of diffusion. The hypothesized of this experiment is that the blue water in dialysis tube 3 will have a faster rate of blue dye diffusing into the salt water in beaker 3. Beaker 1 will have the slowest rate of blue dye diffusing from the dialysis tube into the salt water and beaker 2 will result in a colour in-between beaker 1 and 3. This is because the concentration of salt in the beaker is higher than the water in the dialysis tubes so the salt water will go into the dialysis tube while the blue water in the dialysis tube will diffusion into the beaker. This experiment was performed by measuring out the same amount of water into each of the 3 beakers and adding different amounts of salt to each one to change the concentration. 3 dialysis tubes containing water and 3 drops of blue dye were tied at one end, then tied at the other using cotton thread before placing them one each into the different concentrated beaker cotton tied end facing down. After 20 minutes the results were observed and recorded into the results table. The finishing results were unexpected and not accurate due to the systematic and random errors, rejecting the hypothesis.

Name ____________________________ I) Introduction All cells contain four major types of macromolecules: carbohydrates, lipids, nucleic acids, and proteins. In today’s lab, we will be studying three of the four-proteins, carbohydrates and lipids. Various chemical tests can be used to detect the presence of each of these molecules. Most of the tests involve a color change visible to the eye. If a color change is observed, the test is considered positive. If the color change is not observed, the test is negative, indicating that a particular molecule is not present. In all the chemical tests we will be performing, we will also be using a control. In most cases, the control will be a sample of

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.