Exercise 2: Biomolecules

Four major groups of Biomolecules Proteins Nucleic Acids Carbohydrates Lipids

Proteins are complex molecules made up of any one or more of 20 amino acids

- Provides structural support like collagen and keratin in animals

- Transport protein like hemoglobin and myoglobin

- Enzymes and hormones like insulin and glucagons

- Antibodies for immune defense- Cell membrane proteins and

extracellular matrixNucleic Acids are macromolecules functioning as the chemical constituent of the genetic material (DNA); the cellular ribosomes (RNA) and some of the coenzymes like NAD, FAD, NADP and CoQ

TWO TYPES: DNA deoxyribonucleic acidRNA ribonucleic acid

Carbohydrates (CH2O) functions as the main energy source for organisms, reserve food and the main constituent of the membrane coating of the eukaryotic cells known as the gylcocalyx

Lipids heterogeneous compound- Soluble in organic solvents and

insoluble in water - Main constituent of the cell membrane

phospholipid layer - Main components of sex hormones:

testosterone and progesterone; vitamins A, D, E and K and a concentrated form of food reservoir

- They exist as fats or in oil in nature

COLOR REACTION TESTS FOR PROTEINS

A. BIURET TEST – to determine protein particularly the presence of PEPTIDESINTENSE BLUE-VIOLET COLOR

Determinant: COPPER (II) SULFATE

B. NINHYDRIN TEST – Test for AMINO ACIDS and SHORT PEPTIDE BONDS

Gives out PURPLE or LIGHT VIOLET COLORDeterminant: Ninhydrin reagent; MSG (Monosodium Glutamate); Tablet of Aspartame/Nutrasweet

GENERAL COLOR REACTION TESTS FOR CARBOHYDRATES

A. ANTHRONE TEST - Test for CARBOHYDRATESGives out GREEN colorDeterminant: Anthrone solution (corrosive to the skin)

B. IODINE TEST – Test for all STARCHESGives out DARK-BLUE COLORDeterminant: Iodine solution

ISOLATION OF NUCLEIC ACIDS EDTA – Ethylenediaminetetraacetic acid

A. DNA ISOLATION FROM ONION- Onion + Detergent-Salt-EDTA

mixture- DNA Spooling – whitish thread

of DNA can be collected wrapped around the glass rod

- DNA appears as a whitish insoluble mucus/gel in the tube

- DNA precipitates in cold ethanol B. DISCHE TEST

- DNA from Onion + Diphenylamine reagent + Heat

C. ISOLATION OF DNA FROM ACTIVE DRY YEAST

- Active dry yeast = clear brownish filtrate: CRUDE RNA SOLUTION + Orcinol reagent

TEST FOR LIPIDS Lipids organic solvents: acetone, chloroform, petroleum, ether; insoluble in water

A. SOLUBILITY TEST - Test tubes with Acetone, Ethyl

acetate, Methylene Chloride & Distilled Water + diff. kinds of oils

B. FLAME TEST – for hydrocarbon like compounds