BIOL130 Study Guide - Final Guide: Barium Hydroxide, Paper Chromatography, Reducing Sugar
Document Summary
Lab 1: identification of some macromolecules: positive control = starch and glycogen. Mixture of two different polymers, amylose and amylopectin: amylose = alfa (1 -> 4) linkages [unbranched, amylopectin = alfa (1-> 6) linkages [straight, helical] branched] Glycogen = red brown similar to amylopectin but more branched: multi branched gives the red brown colour. Benedicts test for reducing sugar: sugar can be straight or ring shaped. Makes glucose a reducing sugar: positive test = yellow, green, red, or brown. Cu + reacts with free aldehyde group. Amount is proportional to the [free aldehyde] Ketose sugar (fructose) can also oxidize copper indirectly. Biuret test for proteins: positive contols = peptides and proteins. Detection of peptide bond turns solution violet. Centrifugation: force sediments (pellet) to the bottom of the tube and supernatent to the top (particles of different sizes or properties are separated) Barium hydroxide and sulfuric acid create an insoluble salt leaving a salt free solution.
