BIOL 2281 Study Guide - Final Guide: Biuret Test, Thermus Aquaticus, Diphenylamine
Document Summary
Experiment 6: biochemical testing of macromolecules: know the polymer principle for carbohydrates, proteins and nucleic acids. Polymer principle: macromolecules are polymers consisting of many small repeating molecules called monomers: carbohydrates: polymer of monosaccharides, proteins: polymers of amino acids, nucleic acids: polymer of nucleotides. Copper ion complex with citrate in alkaline solution detects reducing sugars by changing color of benedict reagent. Add 0. 5 ml of benedict"s reagent to each tube, shake tubes, and boil for 5 minutes. Biuret reagent (copper sulfate solution; naoh) reacts with 4-6 peptide (c-n) Sudan iv (fat-soluble dye) selectively absorbed by lipid layer. Diphenylamine reacts with deoxyribose (-h) (nucleotide"s pentose sugar on dna) to produce acidic condition. Two layers, lipid layer should be stained or the dye will sink to bottom. Acidic conditions convert deoxyribose to a molecule that binds with diphenylamine (blue: requires boiling. Negative control: shows what a negative result would look like (no variable)
