LIP I I P D I S & PROTEINS

Transcription

1 LIPIDS & PROTEINS

2 I. LIPIDS: Foods: butter, oil, Crisco, lard Commonly called fats & oils Contain more C-H bonds and less O atoms than carbohydrates. Ex: C 57 H 110 O 6 Nonpolar; therefore repel water (insoluble)

3 I. LIPIDS: Functions of lipids in our body: 1.Long term energy storage (used when carbohydrates are NOT available) 2.Insulation 3.Protect body tissue (cushioning)

4 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!

5 Fats vs. Carbs. & Energy Storage 1 gram of Carbs. (glycogen)= about 4 Kcal of energy a short term rapid energy source (sprint events) 1 gram of Fats = about 9 Kcal of energy a long term energy source(endurance events - marathons)

6 Fats vs. Carbs. & Energy Storage Average human contain about 0.5Kg of stored glycogen = 2,000 Kcal of energy. About 16 1g of body fat = 144,000 Kcal

7 Fats vs. Carbs. & Energy Storage to carry the same amount of energy [144,000 Kcal] as carbs, we would have to store 36 Kg [79.4 lb] more of glycogen to lose 1 Kg of body fat which means, you need to burn lots of calories!

8 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

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

10 Structure of Lipids: One fatty acid: Carboxyl group

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

12 Structure of a lipid (1 glycerol + 3 fatty acids): Glycerol 3 Fatty Acids

13 3 types of fats: 1. Saturated fats = fatty acid chains of carbon with only single bonds between the carbon atoms Bad Fats - cholesterol (heart disease) Solid at room temperature Ex: butter

14 3 types of fats: 2. Unsaturated fats = fatty acid chains of carbon with ONE double bond between the carbon atoms Good Fats Liquid at room temperature Ex: Olive oil

15 3 types of fats: 3. Polyunsaturated fats = more than one double bond between the carbon atoms in the chain Ex: nuts, seeds, fish, leafy greens

16 Structural formulas for saturated and polyunsaturated fatty acids: Polyunsaturated Fatty Acid

17 What happens to LIPIDS in the body? Broken down by the digestive system via HYDROLYSIS into fatty acids and glycerol which are then absorbed into the body through the bloodstream. The fatty acids can then be broken down directly to get energy, or can be used to make glucose

18 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.

19 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

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

21 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

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

23 II. PROTEINS: Foods: meats, soy, cheese Large complex polymer composed of C, H, O, N, & sometimes S Monomers (basic building blocks): Amino acids 20 different amino acids

24 II. PROTEINS: Example amino acids:

25 II. PROTEINS: Structure of an amino acid: Central carbon atom boded with hydrogen. The other 3 bonds are with an amino group (-NH 2 ), a carboxyl group (-COOH) and a variable group(-r) The variable group makes each amino acid different!

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

27 II. PROTEINS: Ex: 2 amino acids joined by dehydration synthesis

28 Peptide bond = a covalent bond that joins amino acids to each other Forms between the amino group of one amino acid and the carboxyl group of another

29 II. PROTEINS: Proteins- named for the number of amino acids that make them Ex: otwo amino acids = dipeptide othree amino acids = tripeptide omany amino acids = polypeptides

30 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. oas a result, it must be provided by our diet. If one is missing then proper growth and repair cannot be maintained.

31 Functions of proteins in our body: 1. Muscle contraction 2. Transport oxygen in the bloodstream

32 Functions of proteins in our body: 3. Provide immunity (antibodies) 4. Carry out chemical reactions

33 What happens to PROTEINS in the body? Broken down by the digestive system via HYDROLYSIS 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.