How Would You Expect Both Positive And Negative Results To Be Affected If You Were To Add Glucose

Organic Molecules These are complex, carbon-containing molecules associated with living organisms. Most also contain hydrogen and oxygen. There are five major types: carbohydrates, lipids, proteins, nucleic acids, and vitamins. Nosotros covered the first three types in lab. A review of our carbohydrate test data is provided on this page. Click the molecule types in a higher place to link to the associated review material.
Benedict's Reagent: A Test for Reducing Sugars Carbohydrates are divided into two groups based on the complexity of their structure. Simple carbohydrates tin can course either a single ring construction (monosaccharides) or a double ring construction (disaccharides -- formed when a pair of monosaccharides bond). Simple carbohydrates include familiar sugars such the monosaccharides glucose (the basic fuel of cells) and fructose (found in fruits). Common disaccharides include sucrose (table carbohydrate) and lactose (the carbohydrate in milk). Complex carbohydrates (polysaccharides) are chains of many bonded simple carbohydrates, and are oft used for free energy storage. These include starch, cellulose, and glycogen. 1 test for the presence of many uncomplicated carbohydrates is to utilise Benedict'due south reagent. It turns from turquoise to yellow or orangish when it reacts with reducing sugars. These are uncomplicated carbohydrates with unbound aldehyde or ketone groups. In lab, we used Benedict's reagent to test for one item reducing sugar: glucose.
Interpreting Benedict's Reagent Results Benedict'southward reagent starts out aqua-blueish. As it is heated in the presence of reducing sugars, information technology turns yellow to orange. The "hotter" the terminal colour of the reagent, the college the concentration of reducing carbohydrate. In general, blue to blue-green or yellow-green is negative, yellowish to bright yellowish is a moderate positive, and bright orange is a very strong positive. (See below).
1: Benedict's Reagent & Water (Negative control).	2: Benedict'south Reagent & Unknown: Negative rx (No reducing sugars).	three: Benedict'due south Reagent & Unknown: Positive rx (Some reducing sugars).	four: Benedict'due south Reagent & Glucose Solution (Positive control).
Terminology review : Controls Water plus Bridegroom's reagent is a negative command for the sugar test. Information technology demonstrates a negative test result (no sugar nowadays). See tube ane above. Glucose plus Bridegroom'south reagent is a positive control for the sugar exam. It demonstrates what a strong positive result should look like. Information technology also proves that our reagents oasis't gone bad (they are capable of producing a positive result). Run into tube iv above. The betoken of controls is twofold. They requite you standards to compare confronting, and they demonstrate that your reagents are working correctly.
Class Benedict's Reagent Results Aside from our controls, we tested three solutions for glucose: starch, acid-treated starch, and amylase-treated starch. As starch is a polysaccharide, it is unsurprising that the starch solution tested negative for simple sugars. We mixed HCl (an acid) into starch and re-tested for simple sugars. Commencement, nosotros had to adapt the pH of the solutions back to neutral before adding the Bridegroom'south reagent. We used a pH indicator and NaOH (a base) for this. We then added the Benedict's reagent. Nosotros got moderately positive results (orangish color). This is considering HCl breaks starch back down into its component monosaccharides (glucose, in this case). Amylase is an enzyme that removes glucose molecules from starch. Both plants and animals use amylase when digesting starch. Unfortunately, amylase cannot break the beta-bonds which hold the glucose molecules together in cellulose. (If it could, we'd be able to eat hay). Based on this data, can you figure out what our results should be if we tested amylase-treated starch and amylase-treated cellulose solutions for reducing sugars?

How Would You Expect Both Positive And Negative Results To Be Affected If You Were To Add Glucose,

Source: https://www.nku.edu/~whitsonma/Bio150LSite/Lab%203%20Organic/Bio150LRevMolec.html

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