The Structure and Function of

Macromolecules

I. Polymers

• What is a polymer?

• Poly = many; mer = part. A polymer is a large molecule consisting of many smaller sub-units bonded together.

• What is a monomer?

• A monomer is a sub-unit of a polymer.

A PolymerA PolymerHere are some analogies to better

understand what polymers and monomers are….

EXAMPLE of POLYMER

MONOMER

A TRAIN THE CARS

A NECKLACE EACH PEARL

A. Making and Breaking Polymers

• How are covalent bonds between monomers formed in the creation of polymers?

• Dehydration synthesis reactions.

• Monomers are linked to one another through the removal of water.

Dehrdration Synthesis

Hydrolysis

• What is a hydrolysis reaction?

• Polymers are broken down into monomers.

• Hydro = water; lysis = loosening/

• Water is added and the breaking or lysis of the polymer occurs.

Hydrolysis

II. Classes of Organic Molecules:

• What are the four classes of organic molecules?

• Carbohydrates

• Lipids

• Proteins

A. Carbohydrates• Sugars

• Carbo = carbon, hydrate = water; carbohydrates have the molecular formula (CH2O)n

• Functions:

• Store energy in chemical bonds

• Glucose is the most common monosaccharide

• Glucose is produced by photosynthetic autotrophs

CARBOHYDRATES

THERE ARE 2 TYPES OF THERE ARE 2 TYPES OF CARBOHYDRATESCARBOHYDRATES

SimpleSimple ComplexComplex

1. Structure of Monosaccharides

• An OH group is attached to each carbon except one, which is double bonded to an oxygen (carbonyl in pink).

Simple Sugars are carbohydrates made up of 1 or 2 monomers. They also taste sweet.

Simple Sugars

Complex Carbohydrates…What are they?

Complex Carbohydrates are polymers Complex Carbohydrates are polymers made up of many monomers.made up of many monomers.

Most also taste starchyMost also taste starchy

Complex Carbohydrates

• Classified according to the size of their carbon chains, some examples vary from 3 to 7 carbons.

Triose = 3 carbons Pentose = 5 carbons Hexose = 6 carbons

2. Structure of Disaccharides• Double sugar that consists of 2

monosaccharides, joined by a glycosidic linkage.

• What reaction forms the glycosidic linkage?

• Dehydration synthesis

Examples of Disaccharides:Lactose = glucose + galactose Sucrose = glucose + fructose

3. Polysaccharides• Structure: Polymers of a few hundred or a few thousand

monosaccharides.• Functions: energy storage molecules or for structural

support: These are examples:

• Starch is a plant storage from of energy, easily hydrolyzed/broken down to glucose units (sugars) Ex: Potato, corn, wheat, etc.

• Cellulose is a fiber-like material - tough and insoluble - used in plant cell walls. We can’t break it down. (1,000’s of sugars long)

• Glycogen is a highly branched chain used by animals to store energy in muscles and the liver. Released from your liver when you get scared. So much energy in it that your hands shake when you are scared, or have adreneline. Sits in your muscles so you can run if needed.

• Chitin is a polysaccharide used as a structural material in arthropod and crustacean exoskeletons.

B. Lipids• Structure: Greasy or oily nonpolar

compounds

• Functions:

• Energy storage 9 calories per gram

• Cell membrane structure

• Protecting against desiccation (drying out).

• Insulating against cold. Fat.

• Absorbing shocks, in joints, and around organs

1. Structure of Fatty Acids• Long chains of mostly carbon and hydrogen

atoms with a -COOH group at one end.• When they are part of lipids, the fatty acids

resemble long flexible tails.

Saturated and Unsaturated Fats• Unsaturated fats : Good

– liquid at room temp– one or more double bonds between carbons in the fatty acids allows for “kinks” in the tails. Tails are

bent and can be broken down. Don’t get caught in arteries.– mostly plant fats; Olive oil, Canola, Corn oil, etc

• Saturated fats: Bad for you

– have only single C-C bonds in fatty acid tails. Lots of Hydrogen bonds– body can’t break them down– solid at room temp– mostly animal fats; butter, red meat fats,

Saturated fatty acid

Saturated fatty acid

Lots of Hydrogens

Unsaturated fatty acid

Has double bonds

3. Phospholipids• Structure: Glycerol + 2 fatty acids + phosphate group.• Function: Main structural component of membranes, where

they arrange in bilayers.

C. Proteins

• Structure:• Polypeptide chains of Amino Acids• Consist of peptide bonds between 20

possible amino acid monomers• Have a 3 dimensional globular shape• Each Protein has a specific order and number

of Amino Acids

1. Functions of Proteins

• Enzymes are proteins which accelerate specific chemical reactions in the body up to 10 billion times faster than they would spontaneously occur.

• Structural materials, including keratin (the protein found in hair and nails) and collagen (the protein found in connective tissue).

• Antibodies are proteins that bind specifically to foreign substances to identify them to the body's immune system.

• Blood proteins, such as hemoglobin, that carry oxygen, iron, and other substances through the body. Muscles, Hormones, and Neurotransmitters in the Nervous system.

• Contraction, such as actin and myosin fibers that interact in muscle tissue.

• Signaling, including hormones such as insulin that regulate sugar levels in blood.

Each of these is an Amino Acid. Bound together in order to make a protein.

Summary of the Organic Molecules: