Lipids The body stores lipids as reserve energy Lipids are hydrophobic water

Lipids the body stores lipids as reserve energy

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Lipids The body stores lipids as reserve energy. Lipids are hydrophobic (“water- hating”) and thus much harder to break down for energy than carbohydrates. Lipids, however, contain more energy per unit weight then carbohydrates. Therefore it is more efficient for the body to use lipids as stored energy. The body will use its carbohydrate source for initial fuel, but if the “fast fuel” runs out, the body will turn to breaking down lipids for a rich energy source. Lipids are fat molecules and there are many different kinds. In this lab, we will study triglyceride molecules , those used by organisms for energy storage. Triglycerides are composed of three fatty acid molecules and one glycerol molecule bonded in an ester linkage. The base elements of these molecules are C, H and O. Like lipids, the chemical Sudan IV is not soluble in water; it is, however, soluble in lipids. Therefore to test for the presence of lipids in a solution you will use a Sudan IV Test . In this test dark red Sudan IV is added to a solution along with ethanol to dissolve any possible lipids. If lipids are present the Sudan IV will stain them reddish-orange, giving a positive test. A positive Sudan IV test in a solution containing nuts.
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Proteins The last macromolecule you will explore in this lab is protein. Proteins are the most complex and functionally diverse molecules of living organisms. Proteins compose enzymes, blood cells and muscle tissue just to name a few and are therefore associated with meat products. Proteins are created by RNA during DNA Transcription and Translation, a process you will learn about in a later lab. The base elements of proteins are C, H, O and N. The monomers of proteins are 20 different amino acids. The amino acids are bonded together in unique combinations to create a polypeptide chain, the protein polymer. This chain is then folded into a unique, functional protein. In this lab you will test for the presence of protein using the Biuret Test . Like the Benedict’s Reagent, Biuret Reagent contains copper ions. These copper ions reflect off closely clustered amide groups of proteins casting a violet color to a solution with proteins. This violet color is a positive reaction in a Biuret Test. All three tubes underwent a Biuret Test. Which is the positive control? Which is the negative control?
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Image of a complex protein. Part I: Testing of Known Substances: Organic Molecules You will learn how to test for each of these organic molecules by clicking on the boxes for Carbohydrates, Protein, fats in the Link above. Complete each of the tests for carbohydrates, proteins and fats. Write your results in the data table below.
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