Nutrition

2. Nutrition • Is the way organisms obtain and use food • Nutrients are the chemical substances present in food which are used by organisms. • They are essential for • metabolism and continuity of life • Uses are • Source of energy • To aid metabolism • For growth and repair

3. 6 Common elements Carbon Hydrogen Oxygen Nitrogen Phosphorus Sulfur 5 Dissolved salts Sodium Magnesium Chlorine Potassium Calcium 14 Food Elements • 3 Trace elements • Iron • Copper • Zinc

4. Biomolecules • Biomolecules: molecules in which atoms of the 14 elements bond together in various ratios. • 4 Major types found in food • Carbohydrates • Lipids • Proteins • Vitamins ( Remember L.C.V.P.)

5. Features Carbohydrates are the body's source of fuel. It provides energy for daily metabolic activities. Simple carbohydratesare found in simple sugars, such as table sugar, honey, corn syrup, cane sugar, brown sugar. Complex carbohydrates are cereals, breads, pastas, and vegetables. Fruit contains both simple and complex carbohydrates. Simple carbohydrates are rapidly digested; complex carbohydrates are digested slowly. *Carbohydrates

6. Carbohydrates What are Carbohydrates ??? • Composed of Carbon, Hydrogen and Oxygen • Ratio of C:H:O is 1:2:1 e.g. C6H12O6 • Exist in the form of: - simple sugars such as fructose, glucose - double sugars as sucrose (cane sugar) lactose (milk sugar), maltose (malt sugar) - multiple sugars such as starch or glycogen.

7. Glucose Molecule C6H12O6

8. 3 Categories of carbohydrates Monosaccharide's - single sugar unit e.g. Glucose and Fructose - sweet to taste - soluble in water Disaccharides - double sugar unit e.g. Sucrose, Maltose and Lactose - sweet to taste - soluble in water Polysaccharides* - many sugars units e.g. Starch (amylose), Glycogen, Cellulose - insoluble/slightly soluble in water

10. Sources

11. Test for reducing sugar- simple sugars

12. Chemicals used: Benedicts solution (blue) • Heat required: yes ( water bath) • Results: colour change from blue to BRICK • RED if sugar is present • Control: water

13. Test for Starch

14. 2. Lipids (Fats and Oils) • Contain Carbon, Oxygen and Hydrogen • No simple ratio of composition • Contain very little oxygen • Fats are lipids that are solid at room temp • Oils are lipids that are liquid at room temp • Sources of lipids – butter, oils, margarine, cream, lard, fat on meat, olives

15. Structure of Lipids Triglycerides The smallest lipids contain one molecule of glycerol linked to 3 fatty acid molecules Phospholipids One fatty acid is replaced by a phosphate group. Play an NB role in cell membrane structure

16. Test for fat

17. Fat Test Worksheet on Food Test

18. Materials used: brown paper • Result: if permanent stain remains on • paper, fat is present • Control: water

19. 3. Proteins • Contain Carbon, Oxygen, Hydrogen and Nitrogen • May also contain small amounts of sulfur and phosphorus • No ratio • Very large and complex molecules • Constructed from building blocks called Amino Acids

20. *Structure of Proteins • Amino acids are biochemical building blocks. • Twenty amino acids are encoded by the standard genetic code and are called standard amino acids. • Rarer, more complicated amino acids are produced by the body and are called nonstandard.

21. Amino acid structure Carboxylic acid group Amine group The R group. This group differs between AA

23. Protein Polypeptide Peptide • Amino acids form short polymer chains called peptides or polypeptides which in turn form structures called proteins.

24. Protein Function • Each type of protein has a different AA sequence • The folding of the AA chain impacts on the function of the protein: • Fibrous proteins show little or no folding. Form strong fibres e.g. keratin, collagen • Globular proteins have well defined folding – specific shape e.g. enzymes • Prions: proteins which do not fold correctly. These proteins are responsible for brain and nervous system diseases – BSE, CJD

25. Sources of Proteins • Sources of proteins are meat, fish, eggs, nuts, milk • Note: the body doesn’t store AA. Broken down in the liver, and the amine group is converted to urea for excretion in the urine.

26. Test for Protein- Biuret test

27. Chemicals used: sodium hydroxide & • copper sulphate • Heat required: No • Results: colour change from blue to • violet if protein is present • Control: water

28. 4. Vitamins • Complex organic compounds that the body can’t make • Needed in tiny amounts • Vitamin D (calciferol) • Fat soluble • Sources: cod liver oil, milk, UV • Helps absorb Ca for bones and teeth • Deficiency – rickets or osteomalacia (brittle bones) • Vitamin C (ascorbic acid) • Water soluble • Sources: fruit and veg • Forms connective tissue, bone and teeth, Helps healing and immune system. • Deficiency - Scurvy

29. Types of energy transfer reactions • Metabolism is the full set of chemical processes (anabolic + catabolic) carried out by a living organism • Anabolic reactionsconvert smaller molecules into larger molecules. They require energy input. • e.g.. Photosynthesis • Catabolic reactionsinvolve the breakdown of large complex molecules into smaller simpler molecules. Catabolic reactions release energy. • e.g.. Aerobic respiration

30. Roles of Biomolecules Biomolecule Carbohydrate Lipid Protein Vitamin Structural role Cellulose in cell walls Energy stores Protection (kidneys) Insulation (under skin) Formation of cell membranes Keratin in hair, nails, hooves Myosin in muscle Metabolic role Primary source of energy Primary source of energy Enzyme, Antibody and Hormone formation. 2nd source of energy Healthy tissue, bone and tooth formation. Healing and immune system function.

31. 6 Common elements Carbon Hydrogen Oxygen Nitrogen Phosphorus Sulfur 5 Dissolved salts Sodium Magnesium Chlorine Potassium Calcium 14 Food Elements • 3 Trace elements • Iron • Copper • Zinc

32. Minerals • Minerals are inorganic nutrients obtained within mineral salts • Functions are • To form rigid structures e.g. Ca in bones, teeth and cell walls of plants • To form soft body parts e.g. S in muscle formation • To function in cellular and body fluids e.g. Fe formation of haemoglobin. Mg formation of Chlorophyll. P formation of ATP

33. Water Water is essential for life for three reasons: • liquid in which all metabolic reactions take place. • provides the basis for transport systems in organisms. • environment in which many organisms live

34. Water • Importance of Water for living things • Component of cytoplasm and body fluids: • - water makes up 75 – 90% of the mass of most cells. • - mainly found in the cytoplasm. • - humans 1/3 of body’s water found outside cells. • B) Good Solvent: • Water can dissolve a wide range of molecules and as a result: • - allows chemical reactions to take place in water, in the cytoplasm and in cell organelles. • - allows many molecules to dissolve in water for transport in plants and animals.

35. Importance of Water for living things C) Participates in chemical reactions: Water is involved in several biochemical reactions - Condensation Reactions – smaller molecules join to form larger molecules with the loss of water e.g. formation of maltose. - Hydrolysis Reactions – a molecule gains water and is broken down to form smaller molecules e.g. breaking of a dipeptide bond. - Photosynthesis* - Respiration* D) Movement through membranes: Water can easily pass in and out of cells giving them the correct shape.

36. Importance of Water for Living things E) Good absorber of heat: Water is a good absorber of heat energy which provides stable temperatures for living things and their reactions.

37. Food Test Summary Table