Grade 12 Biology (SBI4U) Macromolecules

1. Grade 12 Biology (SBI4U)Macromolecules

2. Macromolecules:What you need to know! • Structure of the basic unit (carbohydrates, lipids, proteins, nucleic acids) • How they react to form larger molecules • How the larger molecules are broken down into basic units • Functions of the molecules in living organisms

3. What is a … Polymer

4. "Poly" Greek poly = many, mer = parts Polygons Polyester Polygamy means …

5. Polymers • long molecules • have many similar or identical repeating building blocks (structural units, monomers, small molecules) • connected by chemical bonds (covalent bonds)

6. Monomers • The smallest repeating unit of a polymer • Can exist individually

7. What is a MACROMOLECULE

8. Macromolecules • Organic molecules constructed of smaller units called polymers – these polymers are subdivided into their basic units called monomers + + +

9. Macromolecules • a macromolecule is also called • … biological macromolecule • … biomolecule • … organic molecule • … large carbon-carbon molecule • to name a few…

10. Macromolecules • fall into 4 major categories – can you name them? Hint: 3 of the 4 can be found in foods!

11. Macromolecules: 4 major categories

12. Macromolecules: Question: Which one isn’t considered a polymer and why?

14. Macromolecules: Why do we care? • Macromolecules are the molecules of life! • How do you build a cell? • Start with water, add lots of small carbon-containing • molecules and ……. use these four major classes of macromolecules

15. Macromolecules • All living things are made of cells • Cells are: • ~72% H2O • ~3% salts (Na, Cl, K…) • ~25% carbon compounds (macromolecules)

16. Macromolecules Ions, small molecules (4%) Lipids (2%) Nucleic Acids (DNA and RNA (1% + 6%) Proteins (15%) Carbohydrates (2%)

17. Making and Breaking of Polymers or BREAK MAKE MACROMOLECULES

18. “Condensation” or “Dehydration” Synthesis (aka polymerization) • why synthesis? – a polymer grows in length (a new bond is made) • why dehydration (or condensation) – formation of a water molecule MAKE

19. “Addition” polymerization • monomer molecules added to a growing polymer chain • NO molecules are eliminated in the process • monomer is unsaturated (e.g., had a double bond) • after an addition reaction it becomes saturated Can we add a monomer to a polymer without losing a water molecule? MAKE

20. Hydrolysis (Cleavage) • hydrolysis (hydro = water, lysis = break) – reverses the process of dehydration by breaking down the polymer with the addition of water molecules BREAK

21. Carbohydrates (sugar/starch) • Monosaccharide (b/w 3-7 carbon atoms) • - Contain multiple hydroxyl groups and a carbonyl group • – the simplest sugars • glucose • fructose, • galactose • ribose • deoxyribose • - Contains C, H, O in ratio of 1:2:1

22. Isomers • Isomers – one of two or more molecules with the same number and type of atoms, but different structural arrangements • e.g. glucose, fructose, galactose • - Also differ in chemical and physical properties

23. Carbohydrates • Disaccharides • – 2 simple sugars (sucrose, lactose = glucose + galactose, maltose = glucose + glucose) • - Bond linking monosaccarides together = glycosidic linkage

24. Carbohydrates • Polysaccharides (‘complex’) • – many sugars (e.g. starch, cellulose, glycogen, chitin) • – energy storage • – structural materials glycogen cellulose

25. Carbohydrates (polysaccharides)  Note the linking of simple repeating units

26. Carbohydrates (polysaccharides)

27. Lipids fatty acids • hydrocarbons • comprised of fatty acids • hydrophobic • reservoirs of energy • structural materials • cell membrane • 4 forms of lipids • neutral fats, phospholipids, sterols, waxes

28. Lipids – Neutral fats • neutral fats • three fatty acids and a glycerol • body’s most abundant lipid • functions • energy reservoir • insulation

29. Fats glycerol + 3 fatty acid  fat (triglyceride) Ester linkage

30. Fats

31. Animal vs. Plant Fats

32. Fatty Acids trans-unsaturated fat saturated fat unsaturated fat

33. Lipids – Neutral fats • Can be used for insulation • adipose tissue

34. Lipids - Phospholipids • form double-layered cell membranes

35. Phospholipids Glycerol backbone + 2 fatty acids + phosphate  phospholipid

36. Phospholipids Phospholipids have: • a hydrophobic head • a hydrophobic tail Due to the dual chemical nature of the molecule, it is said to be amphipathic.

37. Phospholipids

38. Phospholipids

39. Phospholipid Bilayer

40. Sterols • also known as steroids

41. Proteins Proteins are used for: • structure • metabolism (enzymes) • immunological protection • molecular transport Proteins are made of subunits of amino acids. Proteins are the most diverse class of macromolecules due to 20 available amino acids.

42. Amino Acids

43. Amino Acids in Aqueous Solutions • Amino acids contain a basic amine group, which can act as a proton acceptor, and an acidic carboxylic acid group, which can act as a proton donor

44. Amino Acids

45. Essential vs. Non-essential Amino Acids Essential Amino Acids: • Cannot be produced by the body, therefore must be consumed in ones diet • 8 essential Amino Acids Non-essential Amino Acids: • Can be produced by the body • 13 Non-essential Amino Acids

46. Peptides amide bond

47. Protein Organization Four layers of protein organization: • primary (1°) structure • secondary (2°) structure • tertiary (3°) structure • quaternary (4°) structure

48. Primary (1°) Structure • sequence of amino acids • polypeptide chain

49. Second (2°) Structure H-bond between peptide bonds a-helix b-pleated sheets not necessarily in all proteins

50. Second (2°) Structure