CARBOHYDRATES MONOSACCHARIDES, DISACCHARIDES, POLYSACCHARIDES

OVERVIEW OF CARBOHYDRATES A carbohydrate is an organic compound that consists only of carbon, hydrogen, and oxygen. Three groups of carbohydrates are: monosaccharides, disaccharides, and polysaccharides In general, the monosaccharides and disaccharides, which are smaller carbohydrates, are commonly referred to as sugars “Saccharide” comes from the Greek language and means “sugar”. The names of the monosaccharides and disaccharides very often end in the suffix -ose.- Polysaccharides serve for the storage of energy (e.g., starch and glycogen), and as structural components (e.g., cellulose in plants and chitin in arthropods).

MONOSACCHARIDES Monosaccharide is a simple sugar consist only of one unit. (“mono” means one) They serve as building blocks for more complex carbohydrate forms. Examples: glucose, galactose (found in milk), and fructose (found in many fruits)

DISACCHARIDES Disaccharides are formed when two monosaccharides are joined together and a molecule of water is removed, a process known as dehydration reaction. Examples: maltose and sucrose (table sugar)

POLYSACCHARIDE Polysaccharides are complex carbohydrates composed of numerous monosaccharides combined through the loss of water molecules. Examples: cellulose (found in plant cell walls), chitin (found in animal exoskeletons), starches Cellulose:

Starch is a storage polysaccharide of plants. It’s is a giant string of glucoses. Glycogen is a storage polysaccharide of glucose in animals. It is stored in the liver and muscles. CARBOHYDRATES ARE USED AS THE MAIN SOURCE OF ENERGY STORAGE

CARBOHYDRATES ARE USED AS STRUCTURAL UNITS Cellulose is a polysaccharide produced by plants. Its is a component of the cell walls. -Cellulose is also a string of glucose molecules. Chitin is an important polysaccharide used to make the exoskeletons of arthropods (insects).

DR. THOMAS J. MONTVILLE 8 LIPIDS

DR. THOMAS J. MONTVILLE 9 FAT STRUCTURE Fats can also be called Triglycerides. Triglycerides are made up of glycerol and some type of fatty acid. Tri means “three”. Glycerol has three carbons so it can get three fatty acids.

DR. THOMAS J. MONTVILLE 10 FAT STRUCTURE Fatty acids are either: saturated: no double bonds, monounsaturated: contain one C=C double bond, or polyunsaturated :contain two or more C=C double bonds Saturated fatty acids stack closely and are more SOLID at room temperature. Unsaturated fatty acids are more FLUID (LIQUID) at room temperature.

DR. THOMAS J. MONTVILLE 11 FAT STRUCTURE Polyunsaturated Fat - Primarily plant sources: vegetable oils (corn, safflower, soybean, sunflower, canola, etc.), margarine (most), mayonnaise, certain nuts (almonds, filberts, pecans, walnuts) Animal Sources: fish Saturated Fat – Primarily animal sources: meat, poultry, milk, butter, cheese, egg yolk, lard Plant Sources: chocolate, coconut, coconut oil, palm oil, vegetable shortening

DR. THOMAS J. MONTVILLE 12 FAT STRUCTURE Monounsaturated Fat Sources: avocado, peanuts, peanut butter, olive/olive oil

DR. THOMAS J. MONTVILLE 13 SUMMARY OF FATS SaturatedUnsaturated Single bond (straight)Double bond (kinked) SolidLiquid Animal (cholesterol)Plants (cholesterol free) FlakyTenderization “Unhealthy”Essential Fatty Acids and ώ-3s Chemically stableD.B.s reactive Cooling as Solid  liquid

DR. THOMAS J. MONTVILLE 14 NUTRITIONAL OVERVIEW OF LIPIDS Fats/Triglycerides  95% of dietary fat  Used as a high density energy storage in animals and in plants (seeds).  May also be used in animals for insulation.  Structure  1 glycerol + 3 fatty acids  Fatty acids  Short, medium, or long chains  Saturated (no double bonds)  Monounsaturated (one double bond)  Polyunsaturated (> one double bond)

DR. THOMAS J. MONTVILLE 15 NUTRITIONAL OVERVIEW OF LIPIDS PHOSPHOLIPIDS  Help make up the cell membrane  Like fats but have two fatty acids and a phosphate group joined to glycerol.  The phosphate group and polar head region of the molecule is hydrophilic (attracted to water), while the fatty acid tail is hydrophobic (repelled by water). Hydrophilic head

DR. THOMAS J. MONTVILLE 16 NUTRITIONAL OVERVIEW OF LIPIDS STEROIDS  Lipids that have a carbon skeleton of four connected rings (no glycerol here)  The different properties of different steroids are due to the attached functional groups.  Cholesterol is a steroid that can be modified to form many hormones such as the sex hormones such as progesterone, estrogen and testosterone.

WAXES Comprised of an ester of a long-chain alcohol and a fatty acid. Many plants have leaves and fruits with wax coatings to help prevent water loss.plants Some animals also have wax-coated fur or feathers to repel water. Unlike most waxes, ear wax is composed of phospholipids and esters of cholesterol. NUTRITIONAL OVERVIEW OF LIPIDS

DR. THOMAS J. MONTVILLE 18 NUTRITIONAL OVERVIEW Functions  Provide energy  Serve as energy reserve  Assist in transport and adsorption of fat-soluble vitamins  Serve as source of essential fatty acids  Insulate and protect organs  Maintain cell walls and play role in making Vitamin D

DR. THOMAS J. MONTVILLE 19 NUTRITIONAL OVERVIEW Food Sources  Oils, sauces, spreads, butter  Meat, poultry, fish, eggs, nuts (fish oil for omega 3s)  Milk, cheese, dairy  Breads cereals and grains with added fats Recommended Intake  Less than or equal to 30% of calories from total fat  Less than or equal to 10% of calories from saturated fat  No more than 300 mg cholesterol

DR. THOMAS J. MONTVILLE 20 FATS IN FOOD Milk: (8 oz. serving) Whole: [3-4 % (legal 3.2%)] 150Kcal 2%: 120 Kcal 1%: 100 Kcal Skim: [<.5%] 90 Kcal Cream: Heavy (Whipping): 36% Light: 18% ½ & ½ : 10.5% Others: Mayo: 65% oil, vinegar, sugar, salt, egg yolk Salad Dressing: 40% oil

DR. THOMAS J. MONTVILLE 21 TAKE HOME: FATS, OILS, LIPIDS Good things about fats  Concentrated source of energy 9 cal/g  Flavor carrier  Imparts texture  Carries fat soluble vitamins, A,D,E,K  Major component of membranes  Makes food taste good

DR. THOMAS J. MONTVILLE 22 TAKE HOME: FATS, OILS, LIPIDS Bad things about fats: Saturated – solid, animal, leads to cholesterol Unsaturated, polyester sucrose, non-digestible, loss of vitamins A, D, E, K  Makes you fat  Coronary disease  Heart disease  Cancer