Macromolecules Unit 5

Macromolecules Living tissue is composed of a diverse array of carbon-based molecules called macromolecules.

Macromolecules The big picture: Macromolecules provide for specific biological activity Provide energy storage Information storage Structural components Catalytic activity

Macromolecules There is a biological unity among all organisms due to the fact that they are composed of four major biological macromolecules

Macromolecules The four classes of macromolecules: – Carbohydrates – primary energy source – Lipids-energy storage – Proteins – structural support, protection, movement – Nucleic Acids – store, transmit, and use genetic info

Macromolecules Vocabulary

Macromolecules - Monomomers -tiny molecules strung in long repeating chains called polymers.

Macromolecules Polymer – are the backbone of the molecule

Macromolecules Hydrolysis of macromolecules Polymers are disassembled or broken down by the process of hydrolysis, as bonds between monomers are broken by the addition of water

Macromolecules Example: – Hydrolysis of starch 1. Start with Starch 2. Introduce the enzyme, amylase, which can break down starch to maltose 3.The enzyme maltase can break down maltose to glucose 4. Glucose ENERGRY

Macromolecules Example- digestion Most of the food we consume is too large to enter our cells. Enzymes within the digestive tract hydrolyze the food into monomers that are absorbed into our blood stream for distribution to all body cells.

Macromolecules Reagent is more specifically a test substance that is added in order to bring about a reaction or to see whether a reaction occurs

Macromolecules Today we will run four tests to find different macromolecules.

Macromolecules 1. Carbohydrates – Most foods contain carbohydrates, which the body breaks down into simple sugars — the major source of energy for the body. – composed of monomers called monosaccharide ( simple sugars) – They can be linked to form disaccharides ( sucrose) – Contain a double-bonded oxygen atom ( carbonyl group)

Macromolecules Benedict’s test for reducing sugars Carbohydrates will react with Benedict’s reagent to form a precipitate that varies in color depending on the sugar concentration.

Macromolecules A color change to yellow, orange or red indicates a positive test for reducing sugars. If test tube color remains blue (the color of Benedict’s reagent) it is a negative result.

Macromolecules Iodine test for starch In the presence of iodine a solution containing starch will turn blue-black in color

Macromolecules Iodine will be added to each of the test tubes. A color change to blue-black indicates a positive test for starch. If test tube color remains yellow-orange (the color of iodine) it is a negative result.

Macromolecules 2.Lipids - structurally diverse that are classified together because they are all insoluble in water (hydrophobic) When mixed with water, lipids clump together as a result of hydrophobic interactions. Lipids include fats, oils, steroids, and waxes.

Macromolecules Sudan IV test for lipids When testing for the presence of lipids in a solution you will use a Sudan IV Test. In this test dark red Sudan IV is added to a solution along with ethanol to dissolve any possible lipids. If lipids are present the Sudan IV will stain them reddish-orange, giving a positive test.

Macromolecules 3. Proteins - Proteins are the most complex and functionally diverse molecules of living organisms. – Proteins compose enzymes, blood cells and muscle tissue just to name a few and are therefore associated with meat products.

Macromolecules We will test for the presence of protein using the Biuret Test. Like the Benedict’s Reagent, Biuret Reagent contains copper ions…………….

Macromolecules These copper ions cast a violet color to a solution with proteins This violet color is a positive reaction in a Biuret Test