Biological Compounds

1. Biological Compounds

2. XS stored as FAT Broken down into glucose Stored as glycogen Carbohydrates Cellular respiration ENERGY Macronutrients ‘BIG’ nutrients – these are complex ‘chemicals’ Glucose + oxygen  water + carbon dioxide + ENERGY

3. Other macronutrients… Lipids: ENERGY stored in body fat and found in membranes Proteins: growth and repair

4. Micronutrients The body only needs VERY SMALL amounts of these Inorganic Ions:Calcium(Ca2+) for teeth, muscles, bones, blood clotting Sodium (Na+) for nerves, heartbeat, muscle contraction Magnesium (Mg2+) Iron (Fe2+) Phosphate (PO43-) Vitamins:complex organic substances water soluble (in blood) e.g. vit C fat soluble e.g. vit A

5. Vitamin C Vitamin C: connective tissue, bones, skin, teeth, endothelial cells deficiency can lead to scurvy can contribute to CVD

6. Water & fibre: (roughage) holds water provides bulk for intestinal muscles to work on

7. Organic Molecules Carbohydrates

8. 2D version Long chain of C atoms The very lazy scientist…. Carbon Chemistry!

9. Branched chain carbon polymer Carbon ring structures Buckminsterfullerine (‘Buckyball’)

10. Carbon Chemistry KEY FACTS Organic molecules contain: Carbon, hydrogen, oxygen, (sulphur, nitrogen, phosphrous) One carbon atom can bond with four other atoms forming a TETRAHEDRAL shape The bits of the body that are not WATER are ORGANIC molecules Carbon can form long chains, branched chains or ring structures They can ‘fold-up’ to make three-dimensional structures

11. Carbohydrates (CHO’s) Sugars: sucrose (white crystalline ‘sugar’) glucose (energy supplier – sports drinks) starch (flour, potatoes) • Carbohydrates fall into four main groups: • Monosaccharides (one ‘sugar-structure’) • Disaccharides (two ‘sugar-structures’) • Oligosaccharides (3-11 ‘sugar-structures’) • Polysaccharides (over 11 ‘sugar-structures’)

12. triose ribose glucose Monosaccharides (‘simple’ sugars) Just one sugar-structure Have an empirical formula of (CH2O)n Triose – found in mitochondria Pentose – found in DNA or RNA Hexose – glucose galactose fructose Empirical formula for hexoses is C6H12O6

13. H OH H C O H C O H C C OH C H OH C H OH H H Isomerism C3H6O3 DIHYDROXYACETONE GLYCERALDEHYDE

14. Ribose & Deoxyribose C5H10O5

15. Glucose

16. Monosaccharides you need to know… SIDE CHAINS AFFECT THE WAY IN WHICH THE MOLECULE IS USED BY THE BODY • all of the carbon atoms are numbered 1-6 • α-glucose has a side chainatposition 6 • fructose has a sidechain at position 1 and position 6

17. Disaccharides

18. Disaccharides • These are 2 monosaccharides JOINED TOGETHER • glucose + glucose makes MALTOSE • glucose + fructose makes SUCROSE • glucose + galactose makes LACTOSE Monosaccharides join together by CONDENSATION REACTION and the bond that joins them together is a GLYCOSIDIC BOND

19. Building a disaccharide

20. Disaccharide summary The three common disaccharides you need to know: All of these are formed by CONDENSATION REACTION (the one you need to be able to draw and label is maltose!!!)

21. Challenge! • See if you can draw the structure of Lactose (that’s glucose + galactose)

22. Breaking apart disaccharides (and polysaccharides)

23. Disaccharides – KEY FACTS Disaccharides are formed from two monosaccharides • glucose + glucose makes MALTOSE • glucose + fructose makes SUCROSE • glucose + galactose makes LACTOSE The reaction that joins two monosaccharides is called a condensation reaction (break them up with hydrolysis) The bond formed between two monosaccharides is called a GLYCOSIDIC BOND – the number of the carbon atoms nearby that are joined gives the bond its name e.g. 1,4 glycosidic bond for maltose

24. Polysaccharides

25. What are they? • Macromolecules • Polymers • Made up of monosaccharide monomers Covalently bonded by Condensation Polymerisation

26. Common ones • Starch • Glycogen • Cellulose • Chitin • All made from glucose Different properties depend on which ISOMER and the type of GLYCOSIDIC bond

28. Starch • Mixture of amylose (30%) and amylopectin (70%) • Amylose: • unbranched chains • 1,4 glycosidic bonds • >300 glucose monomers, helical shape • coils have 6 monomers/turn held together by hydrogen bonds

29. Starch • Amylopectin: • Glucose monomers • 1,4 glycosidic bonded chains • Branches in chains due to 1,6 glycosidic bonds • Branches every 20-30 residues • Molecule several 1000 monomers, very branched and coiled compactly

30. Starch • Functions as storage in plants: • Compact • Insoluble • No osmotic effects • Doesn’t interfere in cell reactions • Easily hydrolysed to sugars when required • Build up into grains in structures called amyloplasts in plant cytoplasm

31. Polysaccharides Complex carbohydrates – many monosaccharides joined together by glycosidic bonds In plants strings of α-glucose joined by glycosidic bonds form starch, which is made up of amylose & amylopectin Amylase breaks the glycosidic bonds from the ends of amylose, and amylopectin (branched) which releases energy

32. Glycogen • Polymer of α-glucose with 1,4 and 1,6 glycosidic bonds • Very similar to amylopectin but it branches more often, every 8 – 12 residues. • Very compact • Energy storage in animals –liver and muscle cells • Cytoplasm of bacteria • Well suited to its role • Compact • Rapidly hydrolysed to sugars when needed Page 6 of molecules handout Question pack

33. Cellulose • Polymer of β-glucose • 1,4 glycosidic bonds forming straight unbranched chains • 1000’s of monomers • Major constituent of the plant cell wall

35. Hydrogen bonding can occur between -OH groups on adjacent chains holding it together

36. Cellulose cont. • Up to 2000 chains can be held together • form microfibril giving high tensile strength

37. Cellulose cont. • Microfibrils embedded in a matrix (like a cement) making it a composite material • Few organisms can break it down (digest) using enzyme cellulase • A few prokaryotes and fungi can

38. What is cellulose called in the field of nutrition? • fibre • Can mammals break down cellulose? • Ruminant mammals have bacteria in gut to do it

39. Anaerobic bacteria in caecum and appendix Anaerobic bacteria in caecum and appendix

40. Chitin • Chitin is used structurally • HOMEWORK – find out more! • Hand in a ‘fact sheet’ on Chitin • Maximum of one side

41. Polysaccharides – key facts Complex carbohydrates – many monosaccharides joined together by glycosidic bonds They often fold-up on themselves to become more complex or are branched The body/plants uses polysaccharides as storage – these molecules can be broken down into smaller components Breaking glycisidic bonds is referred to as HYDROLYSIS and releases a lot of ENERGY Polysaccharides are INSOLUBLE so do not interfere with other chemical functions of the cell and have little impast on osmosis Starch is a polysaccharide found in plants Glycogen is a polysaccharide found in animals

42. Lipids Fats, Oils and Waxes

43. Organic compounds • Insoluble in water • Soluble in organic solvents (eg acetone, ether) • Relatively small (compared to polysaccharides) • Tend to form together into globules Due to not being soluble

44. Naturally occurring fats and oils are esters • Formed by condensation reactions between glycerol (an alcohol) and fatty acids Ester 3 H2O + + Fatty acid Glycerol

45. H H H H – C – C – C – H OH OH OH • Glycerol • C3H8O3 • 3 hydroxyl groups each can undergo condensation reaction with a fatty acid. Produces an ester called a triglyceride (triacylglycerol)

46. Fatty Acid Long non-polar Hydrocarbon chain Polar carboxyl (COOH) end

47. Condensation Reaction

48. Triglycerides Triglycerides containing saturated fatty acids have a high melting point and tend to be found in warm-blooded animals. At room temperature thay are solids (fats), e.g. butter, lard. Triglycerides containing unsaturated fatty acids have a low melting point and tend to be found in cold-blooded animals and plants. At room temperature they are liquids (oils), e.g. fish oil, vegetable oils.

49. Triglycerides They are used for storage, insulation and protection in fatty tissue (or adipose tissue) found under the skin (sub-cutaneous) or surrounding organs. They yield more energy per unit mass than other compounds so are good for energy storage. Water released in oxidisation called metabolic water, important to organisms in dry climates Carbohydrates can be mobilised more quickly, and glycogen is stored in muscles and liver for immediate energy requirements.

50. Like lipids, are esters of glycerol and fatty acids. BUT, one of the fatty acid chains is replaced by a polar phosphate group Phospholipids