Lab 3 Biological Molecules Flashcards
(12 cards)
What is the test for starch
The test for starch is iodine, a deep blue-black colour is formed
What is the test for reducing sugars
Benedict’s test, tests for reducing sugars (many monosaccharides, not disaccharides or polysaccharides). A positive test for the presence of reducing sugar will yield a green (weakly positive), yellow (stronger), orange, brown and, red (strongly positive) precipitate. Different levels of reactivity
What is the test for Lipids?
The test for lipids is Sudan IV, which turns red/orange when in contact with lipids
What is the test for Proteins?
The biuret test detects the bond that forms between amino acids and turns violet colour if proteins are present
What is the Iodine test?
The iodine test for starch, a deep blue-black colour is formed
What is the Benedict’s test?
Tests for reducing sugars (many monosaccharides, not disaccharides or polysaccharides). A positive test for the presence of reducing sugar will yield a green (weakly positive), yellow (stronger), orange, brown and, red (strongly positive) precipitate. Different levels of reactivity
What is the Sudan IV test?
The test detects lipids and turns red/orange when in contact with lipids
What is the Biuret test?
Detects proteins by detecting the bond that forms between amino acids, Turns violet colour if proteins are present
What is a positive control
A positive control is something we know will give a positive reaction.
What is acid hydrolysis?
The process of hydrolysis in the presence of heat and acid.
What is a negative control
A negative control is something we know does not contain the molecule we are testing for and therefore know will give a negative reaction.
What effect does the presence of buffer have on the amount of acid or base needed to change the pH?
The effect of buffers resists change to the pH of the solution, maintaining the pH of a solution by minimizing changes in the concentration of H+. Requires more volume or concentration of the acid/base to change the pH compared to a solution without a buffer.
