Fats and ProteinsFats and Proteins

The good, the bad and the The good, the bad and the othersothers

Fats Fats Fats are a sub-group of Fats are a sub-group of compoundscompounds known as known as lipidslipids that that are found in the body and have the general property of are found in the body and have the general property of

being being hydrophobichydrophobic (meaning they are insoluble in (meaning they are insoluble in water). Fats are also known as triglycerides, water). Fats are also known as triglycerides, moleculesmolecules made from the combination of one made from the combination of one moleculemolecule of glycerol of glycerol

with three fatty with three fatty acidsacids, as depicted below:, as depicted below:

Glycerol

3 Fatty Acids(where R

represents a long C-C-C

chain)

Fat (triglyceride)(where R, R' & R" may or may not be

the same)

Fats can be classified as either saturated or unsaturated Fats can be classified as either saturated or unsaturated depending on the structure of the long carbon-carbon chains depending on the structure of the long carbon-carbon chains in the fatty acids (the R's in the diagram above).in the fatty acids (the R's in the diagram above).

Unsaturated fats contain some number of double bonds in their structure. These fats are generally liquids at room temperature (fats that are liquid at room temperature are referred to as oils). Unsaturated fats can be either polyunsaturated (many double bonds) or monounsaturated fats (one or few double bonds). Recent research suggests that the healthiest of the fats in the human diet are the monounsaturated fats, such as olive oil and canola oil, because they appear to be beneficial in the fight against heart disease.

Fats that contain no double bonds in their fatty acid chains are referred to as saturated fats. These fats tend to be solid at room temperature, such as butter or animal fat. The consumption of saturated fats carries some health risks in that they have been linked to arteriosclerosis (hardening of the arteries) and heart disease.

Proteins Proteins

Proteins are Proteins are polymerspolymers of of amino acidsamino acids. While there . While there are hundreds of thousands are hundreds of thousands of different of different proteinsproteins that that exist in nature, they are all exist in nature, they are all made up of different made up of different combinations of combinations of amino acidsamino acids. . ProteinsProteins are are large large moleculesmolecules that may that may consist of hundreds, or consist of hundreds, or even thousands of even thousands of amino amino acidsacids. . Amino acidsAmino acids all have all have the general structure:the general structure:

General Structure General Structure of an Amino Acidof an Amino Acid

When 2 When 2 amino acidsamino acids bond together, the two bond together, the two ends of nearby ends of nearby amino acidsamino acids (shown above in (shown above in red) are released and the carbon (called a red) are released and the carbon (called a carboxyl) end of one carboxyl) end of one amino acidamino acid bonds to the bonds to the nitrogen end of the adjacent one forming a nitrogen end of the adjacent one forming a peptidepeptide bond, as illustrated below: bond, as illustrated below:

3-dimensional structure of 3-dimensional structure of proteinsproteins

Representation of the 1° structure (amino acid sequence - illustrated with different colors), 2° structure (coiling) & 3° structure (folding) of a protein

PolymersPolymers

The field of The field of polymerspolymers is so vast and the applications so is so vast and the applications so varied, that it is important to understand how varied, that it is important to understand how polymers are made and used. Since there are over polymers are made and used. Since there are over 60,000 different plastics vying for a place in the 60,000 different plastics vying for a place in the market, knowledge of this important field can truly market, knowledge of this important field can truly enrich our appreciation of this wonder material. enrich our appreciation of this wonder material.

Companies manufacture over 30 million tons of Companies manufacture over 30 million tons of plastics each year, and spend large sums on plastics each year, and spend large sums on research, development, and more efficient research, development, and more efficient recycling methods. Below we learn some of the recycling methods. Below we learn some of the scientific principles involved in the production scientific principles involved in the production and processing of these fossil fuel derived and processing of these fossil fuel derived materials known as polymers materials known as polymers

Polymerization ReactionsPolymerization Reactions The chemical reaction in which high molecular The chemical reaction in which high molecular

mass molecules are formed from monomers is mass molecules are formed from monomers is known as known as polymerization. polymerization. There are two basic There are two basic types of polymerization, chain-reaction (or types of polymerization, chain-reaction (or additionaddition) and step-reaction (or ) and step-reaction (or condensationcondensation) ) polymerizationpolymerization. .

Chain-Reaction PolymerizationChain-Reaction Polymerization

One of the most common types of polymer One of the most common types of polymer reactions is chain-reaction (addition) reactions is chain-reaction (addition) polymerization. This type of polymerization is a polymerization. This type of polymerization is a three step process involving two chemical three step process involving two chemical entities. The first, known simply as a entities. The first, known simply as a monomermonomer, , can be regarded as one link in a polymer chain. can be regarded as one link in a polymer chain. It initially exists as simple units. In nearly all It initially exists as simple units. In nearly all cases, the monomers have at least one carbon-cases, the monomers have at least one carbon-carbon double bond. Ethylene is one example carbon double bond. Ethylene is one example of a monomer used to make a common of a monomer used to make a common polymer.polymer.

The other chemical The other chemical reactant is a catalyst. In reactant is a catalyst. In chain-reaction chain-reaction polymerization, the catalyst polymerization, the catalyst can be a can be a free-radicalfree-radical peroxide added in relatively peroxide added in relatively low concentrations. A free-low concentrations. A free-radical is a chemical radical is a chemical component that contains a component that contains a free electron that forms a free electron that forms a covalent bond with an covalent bond with an electron on another electron on another molecule. The formation of molecule. The formation of a free radical from an a free radical from an organic peroxide is shown organic peroxide is shown below: below:

Resin Code

Resin Name Common Uses Examples of Recycled

Products

Polyethylene Terephthalate (PET or PETE)

Soft drink bottles, peanut butter jars, salad dressing bottles, mouth wash jars

Liquid soap bottles, strapping, fiberfill for winter

coats, surfboards, paint brushes, fuzz on tennis balls,

soft drink bottles, film

High density Polyethylene (HDPE) Milk, water, and juice containers, grocery bags, toys, liquid

detergent bottles

Soft drink based cups, flower pots, drain pipes, signs,

stadium seats, trash cans, re-cycling bins, traffic barrier cones, golf bag liners, toys

Polyvinyl Chloride or Vinyl (PVC-V)

Clear food packaging, shampoo bottles Floor mats, pipes, hoses,

mud flaps

Low density Polyethylene (LDPE) Bread bags, frozen food bags, grocery bags Garbage can liners, grocery

bags, multi purpose bags

Polypropylene (PP) Ketchup bottles, yogurt containers, margarine, tubs, medicine

bottles

Manhole steps, paint buckets, videocassette

storage cases, ice scrapers, fast food trays, lawn mower wheels, automobile battery

parts.

Polystyrene (PS) Video cassette cases, compact disk jackets, coffee cups, cutlery,

cafeteria trays, grocery store meat trays, fast-food sandwich container

License plate holders, golf course and septic tank

drainage systems, desk top accessories, hanging files, food service trays, flower

pots, trash cans

Everyday Polymers and their uses