BIO 221 LAB: Organic Molecules I

What do carbohydrates consist of? What is the ratio?

Carbon, hydrogen, and oxygen

1:2:1

Examples of carbohydrates

Monosaccharides, disaccharides, polysaccharides

Function of carbohydrates

1. Source of energy

2. Energy storage

3. Structural

What carbonyl groups do reducing sugars contain

Free aldehyde or free ketone groups

What does the Benedict’s Test test for

Reducing sugars

What do reducing sugars contain

Free aldehyde or a free ketone group

What happens when the Benedict’s reagent detects a reducing sugar?

Solution turns green-reddish orange

How are two monosaccharides linked together and how is that link made?

Linked together through glycosidic bond, bond created by dehydration syntehsis

What are common disaccharides

Sucrose: Glucose + Fructose

Lactose: Glucose + Galactose

Maltose: Glucose + Glucose

What are examples of polysaccharides

Starch and glycogen

What do you test for in the Lugol’s Test?

Polysaccharides

What structure is found in polysaccharides

Alpha helices

What happens when the Lugol’s reagent binds within a alpha helix

Lugol’s reagent will turn brown/black or blue/black

Does starch or glycogen produce a more intense reaction in the Lugol’s test? and why

Starch: Polymers are long with few branches, bind more iodine

Examples for lipids

Fats, Oils, waxes, phospholipids, steroids

What is the function of lipids

Energy storage, membrane structure, fat soluble, hormones

What are lipids characterized by 

C-C and C-H bonds, non-polar, hydrophobic

What are fats composed of

Saturated fatty acids

What are oils composed of

Unsaturated fatty acids

What does the Sudan IV test detect

Lipids

What are proteins made of

Amino acids

What is the bond between proteins called

Peptide bonds

How many naturally occurring amino acids are there

20

What are amino acids made of?

Central carbon, hydrogen, amine group, carboxyl group, side chain/R group

What does the Biuret Test detect?

Polypeptides

What happens when the Biuret Test detects polypeptides?

Copper 2+ is reduced into purple Copper +