LIPIDS & PROTEINS

I. LIPIDS: Commonly called fats & oils Contain more C-H bonds and less O atoms than carbohydrates. Ex: C57H110O6 Nonpolar; therefore repel water (insoluble)

I. LIPIDS: Functions of lipids in our body: Long term energy storage (used when carbohydrates are NOT available) Insulation Protect body tissue (cushioning)

WHICH HAS MORE ENERGY – LIPIDS OR CARBS? One gram of fat contains TWICE as much energy as one gram of carbohydrates. Therefore, fats are better storage compounds!

Types and Examples of Lipids: 1. Sterols- steroids 2. Waxes – bee, furniture, ear, car 3. Cholesterol- in egg yolks, red meat 4. Fats- from animals 5. Oils – from plants

Structure of Lipids: Basic building blocks: 3 fatty acids + 1 glycerol Long chains of carbon with a carboxyl group at one end

Structure of Lipids: One fatty acid:

Structure of Lipids: Glycerol and each fatty acid chain are joined to each other by dehydration synthesis.

Structure of a lipid (1 glycerol + 3 fatty acids):

3 types of fats: 1. Saturated fats = fatty acid chains of carbon with only single bonds between the carbon atoms Solid at room temperature Ex: butter

3 types of fats: 2. Unsaturated fats = fatty acid chains of carbon with ONE double bond between the carbon atoms Liquid at room temperature Ex: Olive oil

3 types of fats: 3. Polyunsaturated fats = more than one double bond between the carbon atoms in the chain

Structural formulas for saturated and polyunsaturated fatty acids:

What happens to lipids in the body? Broken down by the digestive system into fatty acids and glycerol which are then absorbed into the body through the bloodstream, where the body cells take the fatty acids and glycerol and make needed lipids

I. Lipids: Triglycerides = Majority of fat in organism consist of this type of fat molecules Derived from fats eaten in foods or made in the body from other energy sources like carbohydrates.

I. Lipids: Calories ingested in a meal and not used immediately by tissues are converted to triglycerides and transported to fat cells to be stored. Storage – 3 month supply of energy vs. glycogen’s 24 hour supply

I. Lipids: Hormones regulate the release of triglycerides from fat tissue so they meet the body's needs for energy between meals.

Excess Triglycerides- Life Applications: Cause plaque to build up Arteriosclerosis = walls of the arteries get thick and hard; fat builds up inside the walls and slows the blood flow Cause blood clots – heart attacks, strokes

Excess Triglycerides- Life Applications: Hypertension (high blood pressure)

II. PROTEINS: Large complex polymer composed of C, H, O, N, & sometimes S Basic building blocks: Amino acids 20 different amino acids

II. PROTEINS: Example amino acid:

II. PROTEINS: Amino acids are linked together by dehydration synthesis to form a protein

II. PROTEINS: Ex: 2 amino acids joined by dehydration synthesis (dipeptide)

II. PROTEINS: Peptide bond = a covalent bond that joins amino acids to each other

II. PROTEINS: Proteins- named for the number of amino acids that make them Ex: two amino acids = dipeptide three amino acids = tripeptide many amino acids = polypeptides

II. PROTEINS: Essential Amino Acids: 10 of the 20 amino acids are “essential” because they are required by the body but are not created by it. As a result, it must be provided by our diet. If one is missing then proper growth and repair cannot be maintained.

Functions of proteins in our body: Muscle contraction Transport oxygen in the bloodstream

Functions of proteins in our body: 4. Carry out chemical reactions Provide immunity (antibodies)

What happens to PROTEINS in the body? Broken down by the digestive system into amino acids which are then absorbed into the body through the bloodstream, where the body cells take the amino acids and makes protein for muscles.