Lipid Macromolecules Lab Report

3.List whether each of the following substances was positive or negative for starch, as indicated by using iodine. (7 points)

Macromolecules play a crucial role in the functions of living systems, and so it is important to be able to identify what substances might contain specific macromolecules. In this experiment, three tests were conducted on twelve sample solutions of different substances. The macromolecules being tested for were polysaccharides such as glycogen and starch, reducing sugars, and finally proteins. These three types of macromolecules were tested using the Iodine Test, Benedict’s Test, and Biuret Test respectively. The overall purpose of this experiment was to develop an understanding of why certain macromolecules might react with certain substances given their unique properties, as well as to identify an unknown substance based on the results of these tests.

In conclusion, I have acquired a new knowledge about how to test for macromolecules in food such as carbohydrates, starch, proteins, and lipids. To begin with, I knew that potato do have sugar in them so it will definitely have positive reaction and I was right about that. When you add Benedict's solution to a food that contains sugar, the food will change its colour from blue to green to reddish brown and the same thing happened to potato. Furthermore, the sucrose solution and distilled water contains starch because when drops of iodine were added into these liquids they changed their colour into yellowish-brown which indicates the sign of the starch in these substances. In addition, an egg albumin solution and milk contains protein in them

The purpose of this lab was to test 12 different aqueous solutions containing macromolecules, 11 of which were controls while the final one was an unknown. Three different test were carried on each of the 12 samples. The first was an iodine test for the presents of either starch and glycogen in the sample. Iodine is a clear colourless liquid before being added to any of the solutions. The way starch is identified is by the solution turning blue-black.The solution does this because of the amylose in the starch, amylose and amylopectin are the two parts that make up a starch, amylose is made up of 200 to 5,000 alpha -D-glucose, which coil into a tight spring structure(Toole, 2004). When the iodine is added it is pushed by the starch into the middle of this coil this creates a tight helix and this turns the solution black/ dark blue.(Ophardt, 2003) The way Glycogen is identified is when the solution turns reddish-brown. Glycogen is very similar to amylopectin as it is made up of alpha glucose units joined at 1-4 and 1-6 and it is a branched structure. (Toole, 2004) Iodine affects glycogen similarly as it does amylose.

Introduction The purpose of this lab was to study cell physiology. This is described as the scientific procedure that studies the functions of cells growth and their maintenance, self-regulation, their divisions and interactions. This involve their functions through the nucleus, cytoplasm, and general behavior of protoplasm. Physiology is the science that analyzes the functionality of living organisms, its structures, and the chemical and physical aspects involve in it. While people analyze cells components, they can notice the development of cells and how they get untied to form organs and other structures.

When Benedict’s reagent was added to the glucose solution it turned to a dark orange-red, indicating a high sugar concentration. Next we added Benedict’s reagent to the starch solution which remained blue, indicating no sugar presence. The onion juice also turned a red-orange color as a reaction to the addition of Benedict’s reagent indicating a very high sugar concentration. Lastly, when Benedict’s reagent was added to potato juice a yellow-orange color was visible, indicating a moderate concentration of sugar.

When starch is mixed with iodine, the beta amylose molecules found in the starch trap iodine, causing the mixture to turn a bluish black color (Senese, Fred). However, when the starch is broken down into glucose, the substance does not react to the iodine, resulting in the glucose in the mixture not changing color. Additionally, when amylase is mixed with a bluish black mixture

During the experiment, the aim was that students will be able to learn and practise the biological/scientific skills essential to investigate whether chlorophyll, light and carbon dioxide is necessary for the production of starch. In this experiment, the students predicted that chlorophyll, carbon dioxide and light are needed to be present in a leaf to produce starch successfully.

what help create all the living things we see everyday. Lipids are found in all membranes, mainly

The purpose of this lab is to determine the type of macromolecules that make up a particular unknown solution; using 3 different chemical tests. The first test consists of adding Benedict’s reagent to 12 different solutions; including the unknown. If any of the 12 solutions undergo a reaction in which they change colour (yellow, green, red or brown), then; the solutions contain simple sugars (ex. Monosaccharides).

In contrast, there is glucose that is considered a “simple sugar or a monosaccharide” due to its structure (Georgia State University). Most foods made of glucose molecules are used as sources of energy for animals as ATP (Georgia State University). Both these sugars are in our diets, yet they are quiet different in chemical structure and physical form. This is why a substance that contains starch, does not always contains glucose (Shorter KR). To test for these two carbohydrates, two different tests were developed: Lugol’s and Benedict’s. Lugol’s indicates whether or not a substance contains starch, and if so, how much (Shorter KR). This is determined based on a color scale (5 different shades), from amber to a bluish black (Shorter KR). The farther down the scale, the more starch the substance contains. Likewise, the Benedict’s solution indicates the amount of starch as the 8-color shades (light blue to dark green) progress (Shorter KR).

The word protein originates from the Greek word protos which denotes "the first rank of importance", in all biological systems we find macromolecules called proteins which range from as low as prokaryotes to higher eukaryotes. Naturally proteins are complex in nature performing numerous functions that sustain life. Besides other polymers for instance nucleic acids, polysaccharides, or lipid assembles, proteins account for almost over 50% of the total dry weight of cells, They occupy the largest percentage in living cells both quantity and quality .

Starch-based snacks and ready-to-eat breakfast cereal continue to increase in sales worldwide. Starch-based snacks are commonly made in the form of puffed products. Puffed products are appreciated mainly for their lightness and crispness. These qualities are related to the air cellular structure and degree of expansion. Puffing is a process used for engineering structures and properties of food materials to give a light, airy and crispy texture (Nath and Chattopadhyay, 2008; Mariotti et al., 2006). Process for making starch-based puffed products includes gelatinization of starch, cooling, drying, and then explosive expansion (Hoke et al., 2007). After starch gelatinization, retrogradation of starch molecules, amylose and amylopectin occurred during cooling and aging of the pastes (Perdon et al., 1999; Ji et al., 2007; Mariotti et al., 2009). The amylose-amylopectin ratio, which commonly reported in term of amylose content, has been known to be an important parameter affecting physical properties of starch pastes/gels and characteristics of puffed products (Hibi and Hikone, 1998; Boischot et al., 2003; Cheow et al., 2004; Saeleaw and Schleining, 2010). The retrograded amylose prepared for the crystal nuclei, which can increase the nuclei crystal growth, so the higher amylose content, the faster starch retrograded (Biliaderis, 1992) which showed high retrogradation enthalpy (Vandeputte et al., 2003; Narpinder et al., 2006) and provided the harder gel. For rice flour

When added with iodine solution, all of the starch solutions turned blue-black colour. Starch contains long linear chains which are called amylose. Amylose coils into a helical secondary structure resembling a tube with a hollow core. Therefore, the chemical complex of iodine can assembles inside the amylose to produce a characteristic blue-black colour (Jeffery, 2007).

Before the hypotheses could be tested, the identification of starch and maltose was tested separately. To observe the presence of starch, one drop of IKI was placed in three wells of a spot plate. Two drops of water were added to the first well, two drops of starch were added to the second well, and two drops of maltose were added to the third well. The results of the independent