1. Biological Compounds

2. Macronutrients ENERGY ‘BIG’ nutrients – these are complex ‘chemicals’
XS stored as FAT
Broken down into glucose
Stored as glycogen
Carbohydrates
Cellular respiration
ENERGY
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. Carbon Chemistry! 2D version Long chain of C atoms
The very lazy scientist….

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

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

14. Ribose & Deoxyribose
C5H10O5

15. Glucose

16. SIDE CHAINS AFFECT THE WAY IN WHICH THE MOLECULE IS USED BY THE BODY
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 chain at position 6
fructose has a side chain 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. (break them up with hydrolysis)
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

27. Polysaccharide Monomer Glycosidic Bond Molecule Shape 1,4
Starch
α-glucose
(amylose)
1,4
Unbranched wound into a helix
(amylopectin)
1,4 with some 1,6
Tightly packed branched chain
Glycogen
1,4 with more 1,6 than amylopectin
Very branched compact molecule
Cellulose
β-glucose
Unbranched straight chains

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 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

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. Soluble in organic solvents (eg acetone, ether)
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 +
Fatty acid
Ester
Glycerol +
3 H2O

45. each can undergo condensation reaction with a fatty acid.
H – C – C – C – H H 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. Phospholipids
Like lipids, are esters of glycerol and fatty acids. BUT, one of the fatty acid chains is replaced by a polar phosphate group

51. Phospholipid

52. Phospholipids
Polar (phosphate) group is soluble in water
The fatty acid chains are not
So at air-water or oil-water interfaces, phospholipids orientate so the polar head is in the water.
Important constituent in cell membranes.

53. Fats and health. Saturated or unsaturated? Which is best?
What are the risks of the wrong type?
How much is too much?
Who says?
What’s BMI?
Question Pack