Organic Molecules Lab

Organic Molecules Lab - Rachel Romm Biology 1H Ms. Mackley...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Rachel Romm Biology 1H Ms. Mackley 17 October 2008 Partner: Sungwon Oh Organic Molecules Lab
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Problem: What would happen if a chemical test were performed on a substance? Objective: To learn the properties of three organic molecules: carbohydrates, proteins, and fats, by performing a chemical test. Part 1 Objective: Part 2 Objective: Identify polysaccharides using Lugol’s reagent. Part 3 Objective: Distinguish between lipid and non-lipid substances using the Sudan IV test. Part 4 Objective: Distinguish between free amino acids and proteins (polypeptides) on the basis of their ability to react with biuret. Part 5 Objective: Identify free amino acids and proline using ninhydrin. Hypothesis : If a chemical test is performed on the substances then, some substances will test positive for an organic molecule. Part 1 Hypothesis: If Benedicts is added to the solutions than, the solutions with reducing sugars will test positive. Part 2 Hypothesis: If Lugol’s reagent is added to the solutions then, the solutions with polysaccharides will test positive. Part 3 Hypothesis: If Sudan IV is added to the solutions then, it will dissolve in the lipids. Part 4 Hypothesis: If biuret is added to the solutions then, the solutions with free amino acids and proteins will test positive. Part 5 Hypothesis: If ninhydrin is added to the solutions then, the solutions with free amino acids and proline will test positive.
Background image of page 2
Intro: Carbon-containing molecules or, organic molecules are vital to most cells. Organic molecules can mostly be classified into four categories: carbohydrates, fats, proteins, or nucleotides. Each category of organic molecules has specific properties that can be found by performing a chemical test. Monosaccharide , a simple sugar, is the basic structural unit of a carbohydrate. Monosaccharides are classified by the number of carbons they contain. For example, trioses contain three carbons and, pentoses contain five carbons. Monosaccharides can have as little as three carbons to as many as ten. The presences of a terminal aldehyde group or an internal ketone group characterize a monosaccharide. Both aldehydes and keytones contain a double-bonded oxygen atom that reacts with Benedicts reagent to form a colored precipitate. A disaccharide is formed when two monosaccharides are joined together. A disaccharide will not react with Benedicts reagent if the reactive aldehyde or ketone groups are involved in the bonds between two monosaccharides units. This can be seen in sucrose. If only one aldehyde or ketone group is involved in the bonding, the other monosaccharide can react with the benedicts. Reducing Sugars are sugars with a free aldehyde or ketone group. The carbonyl group (C=O) is oxidized to carboxylic acid (COOH) and in the process loses an electron, which is picked up by the CuSO 4 in Benedicts. This reduces the Cu(II) ions (blue) to Cu(I), which are orange. Polysaccharides
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/25/2010 for the course BIO 5381 taught by Professor Smith during the Spring '10 term at N. Arizona.

Page1 / 8

Organic Molecules Lab - Rachel Romm Biology 1H Ms. Mackley...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online