1 / 30

Nutrition

Nutrition. Why do we need food? Energy Provides raw materials for growth and repair Makes chemicals needed for metabolic reactions The 6 most common elements in food are : Carbon (C) Hydrogen (H) Oxygen (O) Nitrogen (N) Phosphorous (P) Sulphur (S).

donal
Download Presentation

Nutrition

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nutrition

  2. Why do we need food? • Energy • Provides raw materials for growth and repair • Makes chemicals needed for metabolic reactions • The 6 most common elements in food are: • Carbon (C) • Hydrogen (H) • Oxygen (O) • Nitrogen (N) • Phosphorous (P) • Sulphur (S)

  3. Other elements occur in smaller numbers: 5 as dissolved salts • Sodium (Na) • Magnesium (Mg) • Chlorine (Cl) • Potassium (K) • Calcium (Ca) 3 as trace elements (only needed in tiny amounts): • Iron (Fe) • Copper (Cu) • Zinc (Zn)

  4. The 6 groups of Biomolecules are: • Carbohydrates • Lipids (Fats and Oils) • Proteins • Vitamins • Minerals • Water

  5. CarbohydratesCarbon (C), Hydrogen (H) & Oxygen (O) • In the form of Cx(H2O)y • Made of sugar units: • Monosaccharides • Disaccharides • Polysaccharides

  6. Monosaccharides • Smallest unit of carbohydrate • Sweet • Soluble in water • Glucose • Fructose

  7. Disaccharides • Two monosaccharides joined together • Sweet • Soluble in water • Sucrose (table sugar)=glucose + fructose • Maltose=glucose +glucose

  8. Polysaccharide • Many monosaccharides joined together • Insoluble in water • Starch • Cellulose • Glycogen

  9. Functions of Carbohydrates • Provides energy (Metabolic Role) • Howeverif too many carbohydrates are consumed it will be converted to fat and stored • Cellulose in plant cell walls (Structural Role) • Cellulose also has the function of preventing: • Constipation • High Blood Cholesterol

  10. Lipids(Fats and Oils) Carbon (C), Hydrogen(H) and Oxygen(O) • Less oxygen than Carbohydrates • Fats are solid at room temp, oils are liquid • Lipid structure varies; • Triglyceride(normal lipid): one glycerol with 3 fatty acids joined to it • Phosopholipid: one glycerol, 2 fatty acids and a phosphate group joined to it

  11. Triglyceride

  12. Functions of Lipids • Lipids release energy in respiration (Metabolic role) • They also form a protective layer around delicate organs such as the heart (Structural role) • They act as an insulator, stored as adipose tissue under the skin • Lipids are insoluble in water but soluble in alcohol • Sources of lipids include butter and cod liver oil.

  13. ProteinsCarbon(C), Hydrogen (H), Oxygen (O) and Nitrogen (N) • Made of amino acids joined together in different ways • 26 amino acids in total

  14. Dipeptide is a chain of 2 amino acids (think 2 marbles joined) • Tripeptide is a chain of 3 amino acids • Peptide is a chain of less than 20 amino acids • Polypeptide is a chain of many amino acids (apx 500) • There are essential amino acids which cannot be made by animals and must be consumed in the diet (9 in total)

  15. Fibrous Protein: have very few or no foldings e.g. keratin in hair and nails • Globular Protein: have lots of foldings e.g. Enzymes

  16. Prions are proteins that do not fold incorrectly • Eg: Creutzfeldt–Jakob disease and BSE

  17. Protein Functions • Form enzymes and hormones (Metabolic Role) • Present in hair, nails and muscle (Structural Role)

  18. Sources: Meat, Fish, Eggs and Nuts

  19. Vitamins • Most Vitamins cannot be made by the body • Only needed in small amounts • Water Soluble Vitamins: B group and C • Fat Soluble Vitamins: A/D/E/K

  20. Vitamin C • Found in Oranges, forms connective tissue. • Deficiency Scurvy: Bleeding gums, loose teeth

  21. Scurvy

  22. Vitamin D • Found in Cod liver, for healthy bones. • Deficiency Rickets.

  23. Minerals • Necessary in small amounts • Form structures e.g. Calcium forms bones and cell walls • Forms soft body tissue e.g. Muscles • Maintains concentration of cells and body fluids • Minerals needed by plants and animals vary.

  24. Animals: • Calcium, found cheese, forms bones and teeth • Iron, found in liver and green vegetables, forms part of haemoglobin • Plants: • Calcium, absorbed from soil, forms calcium pectate in cell walls • Magnesium, absorbed from soil, is part of the structure of chlorophyll

  25. Water • Water makes up the major body cells and helps them to keep their shape • It helps transport materials in and out of cells • It is a good solvent • Necessary for photosynthesis

  26. 2010 Section A Q1 Higher

More Related