Importance of Nutrition

Transcription

1

2 The EAT WELL Plate

3 Canada s food guide

4 Food pyramid

5 Importance of Nutrition Energy for body metabolism (nerve impulses, contraction of muscles, repair and replacement of cells Raw materials for building blocks of cells (proteins for muscles, calcium for bones, fats for cell membranes)

6 Essential Nutrients Macronutrients: nutrients taken in large amounts daily, provide energy: carbohydrates, proteins, fats Micronutrients: minerals, vitamins Water is essential for survival!

7 Macronutrients

8 Carbohydrates major sources of energy, quick energy source organic molecules: C, H, O Monosaccharide (C6H12O6 ) Disaccharide (C12H22O11 ) Polysaccharide

9 Monosaccharides- simple sugars fructose (in fruits, honey) galactose (in milk) glucose (in starch) all 3 forms have the same chemical formula C6H12O6 but in different arrangements dehydration synthesis or condensation removing a water molecule to combine 2 monosaccharide molecules forming a disaccharide

10 Disaccharides glucose + glucose maltose + water ** hydrolysis can break maltose easily into two glucose molecules

11 Disaccharides glucose + fructose sucrose + water *sucrose : common table sugar hydrolysis can break sucrose easily into glucose and fructose

12 Disaccharides glucose + galactose lactose + water *lactose: sugar in milk

13 Polysaccharides- Starch Stored in grains and vegetables

14 Polysaccharides- Glycogen made by animals excess glucose is converted to glycogen by hormone insulin and stored in the liver can be converted back by hormone glucagon when the blood sugar level is low

15 Polysaccharides- Cellulose In plant cell walls not digested in the human intestine, but provides roughage in the intestine for waste elimination

16 Fats Make up phospholipid bilayer in the cell membrane (contain phosphates, lipids, cholesterol) Surround and protect vital organs and joints, fats underneath skin insulate body Organic molecules: C, H, O with different ratios from carbohydrates

17 Fats - structure triglyceride = a 3-C glycerol molecule + 3 fatty acids (long chain of C s with an acid group at the end) Unsaturated fat

18 Saturated vs. Unsaturated Saturated fats: all the carbon branches are filled with hydrogen, solid at room temp. animal fat, butter, lard, hard margarines (saturated artificially) Unsaturated fats: not all carbon branches are filled with hydrogen, liquid at room temp. vegetable oil, nut oils, some fish oils, some margarines

19 Phospholipid Bilayer Cell Membrane Hydrophilic head (phosphate + nitrate + glycerol) and hydrophobic tail (2 fatty acids) Hydrophilic water loving Hydrophobic water fearing

20 Phospholipid bilayer

21 Cholesterol soft, waxy lipid in body cells, in arteries and veins, on cell membranes, insulate nerves, produce vitamin D, bile acids and hormones, rich in meat, shellfish, whole-milk products, eggyolks

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24 Lipoprotein contains both proteins and lipids (phospholipids) on the outside transport fats (triglycerides) and cholesterol in waterbased bloodstream

25 Proteins Provide structure within the body, muscles, skin, nails, hair, organs, cells membrane protein channels, antibodies and enzymes Organic molecules, contain C, H, O, and N (text p. 15) Polypeptides are broken down to dipeptides and amino acids with the help of digestive enzymes

26 Proteins All proteins are built from a set of 20 amino acids 8 of them are not made in the body, so must be obtained from food, therefore called essential amino acids a complete protein= protein that is made up of the 8 essential amino acids (in meat, legume, milk, egg, cheese, whole grain)

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28 Micronutrients Vitamins + Minerals

29 Vitamins Serve as coenzymes (make enzymes function), help tissue growth, defense against diseases Fat- soluble: K, E, D, A (eyes and skin) Water-soluble: B, C (antioxidant, resist disease), excess vitamins are removed in the urine K and B (body metabolism, antibody) are produced in the intestines Body can produce D when exposed to sunlight vitamins A, B1, B2, C, D, folic acid, niacin, E, K?

30 Minerals Inorganic, do not contain carbon Help in chemical reactions, help build bones and cartilages, hormones, Ca- bone formation, nervous signals P-bone formation, build cell membrane, nucleic acids, ATP K- nerve impulse Na- nerve impulse, osmotic balance Fe- hemoglobin synthesis (red blood cells) I- thyroid hormone Cl - water balance, Zn- enzyme synthesis, growth, Se tissue elasticity, Cu-hemoglobin synthesis