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GRADE 12 BIOLOGY (SBI4U) MACROMOLECULES. 2 Macromolecules: What you need to know! 1. Structure of the basic unit (carbohydrates, lipids, proteins, nucleic.

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Presentation on theme: "GRADE 12 BIOLOGY (SBI4U) MACROMOLECULES. 2 Macromolecules: What you need to know! 1. Structure of the basic unit (carbohydrates, lipids, proteins, nucleic."— Presentation transcript:


2 2 Macromolecules: What you need to know! 1. Structure of the basic unit (carbohydrates, lipids, proteins, nucleic acids) 2. How they react to form larger molecules 3. How the larger molecules are broken down into basic units 4. Functions of the molecules in living organisms

3 What is a … 3

4 Polyester Polygamy Polygons 4

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

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

7 7

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

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

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

11 11 Macromolecules: 4 major categories

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

13 13

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

15 Macromolecules 15 All living things are made of cells Cells are: ~72% H 2 O ~3% salts (Na, Cl, K…) ~25% carbon compounds (macromolecules)

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

17 Making and Breaking of Polymers MAKE BREAK or

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 MAKE Can we add a monomer to a polymer without losing a water molecule?

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 21

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 22

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

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

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

26 26

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

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

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

30 Fats

31 Animal vs. Plant Fats Animal FatsPlant Fats - Triglycerols containing mostly saturated fatty acids -triglycerols are unsaturated and polyunsaturated FA - Straight hydrocarbon chains allowing for van der Waal attractions -Hydrocarbon chains have double bonds and many kinks, ↓ van der Waal attractions - Solid at room temperature- Liquid at room temperature

32 Fatty Acids saturated fat unsaturated fat trans-unsaturated fat

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

34 Lipids - Phospholipids form double-layered cell membranes 34

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

36 Phospholipids Phospholipids have: 1. a hydrophobic head 2. a hydrophobic tail Due to the dual chemical nature of the molecule, it is said to be amphipathic.

37 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: 1. primary (1°) structure 2. secondary (2°) structure 3. tertiary (3°) structure 4. quaternary (4°) structure

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

49 Second (2 ° ) Structure  H-bond between peptide bonds   -helix   -pleated sheets  not necessarily in all proteins

50 Second (2 ° ) Structure

51 Tertiary (3 ° ) Structure  provides protein a final 3-D structure  four major bond types between R groups of amino acids 1. H-bonding 2. ionic bonding 3. hydrophobic interactions 4. covalent bond (disulfide bridge)

52 Tertiary (3 ° ) Structure

53 General Protein Shapes  Globular Proteins (Hemoglobin)  Fibrous Proteins (Tropomyosin & Keratin)

54 Quaternary (4 ° ) Structure  fully functional protein requires all subunits present  not all proteins have quaternary structure

55 Protein Properties Proteins have optimal conditions at which they function. When exposed to extreme conditions, proteins begin to unfold – denature. If denaturation occurs moderately over time, returning to the original conditions may result in renaturation.

56 Protein Folding Proper folding in the cell is completed by chaperonin molecules. Utilizes ATP to help proteins fold properly.

57 Nucleic Acids Nucleic acids are used for:  maintaining genetic continuity  delivering information for protein synthesis  energy molecule (ATP – adenosine triphosphate) Two major nucleic acid polymers: 1. DNA – deoxyribonucleic acid 2. RNA – ribonucleic acid

58 Nucleic Acids DNARNA  located in the nucleus  double-stranded, double helix structure  stable molecule  mainly found in cytoplasm  single-stranded structure  unstable molecule

59 Nucleotides The basic subunit of nucleic acids is a nucleotide. Three components: 1. phosphate 2. pentose sugar 3. nitrogenous base

60 Pentose Sugar

61 Nitrogenous Bases purines pyrimidines

62 Nucleic Acid  reaction between 1. pentose sugar OH group of one nucleotide 2. phosphate group of another nucleotide  forms phosphodiester bond

63 In Conclusion  The building blocks (monomers) of macromolecules are amino acids, nucleotides, simple sugars, and fatty acids

64 In Conclusion Name the two main chemical reactions shown making and breaking organic molecules

65 In Conclusion  Carbohydrates are use for energy storage and as structural materials  Lipids are used as energy storage and structural components  Proteins are made of amino acids which form structures, enzymes, transport, movement, and are part of the immune system  Nucleic acids are the basis of inheritance and reproduction

66 In Conclusion  The versatility of carbon makes possible the great diversity of organic molecules  Variation at the molecular level lies at the foundation of all biological diversity

67 MacromoleculeExample(s) of subunits Main functionsExamples of macromolecules carbohydratessugars (such as glucose) and polymers of glucose energy storagesugars, starches, and glycogen lipidsglycerol and three fatty acids or glycerol and two fatty acids energy storage and cell membranes fats, oils, and phospholipids proteinspolymers of amino acidstransport, blood clotting, support, immunity, catalysis, and muscle action hemoglobin, fibrin, collagen, antibodies, enzymes, actin, and myosin nucleic acidspolymers of nucleotidestransfer and expression of genetic information DNA and RNA 67 Answers to post-presentation activity #1 – the activity could be use alone as a pre-assessment (what should be known from Grade 11 SBI3U)

68 68 Day 2

69 In building large macromolecules carbon usually combines with other carbons … AND with one or more functional groups 69

70 70 Why study Functional Groups? These are the building blocks for organic molecules (or macromolecules – large organic molecules)

71  the components of organic molecules most commonly involved in chemical reactions  the number and arrangement of functional groups give each organic molecule unique properties Why study Functional Groups?

72 72 Types of functional groups 6 functional groups most important to chemistry of life:  hydroxyl  amino  carbonyl  sulfhydryl  carboxyl  phosphate

73 73 Functional groups they affect reactivity (e.g., hydrophilic, increase solubility in water)

74 Hydroxyl  organic compounds with OH = alcohols  alcohols, carbohydrates, nucleic acids, some acids, and steroids  highly polar (makes molecules more soluble)  e.g., ethanol

75 75 Carbonyl  if C=O at end molecule = aldelhyde  if C=O in middle of molecule = ketone  react with molecules (H-R 2 ) to form H-R 2 -C-OH  a ketone and an aldehyde may be structural  isomers with different properties, e.g., acetone and propanal

76 76 Carboxyl  compounds with COOH = acids  fatty acids, amino acids  acidic – tends to lose a proton (COO - )  involved in peptide bonds  e.g., acetic acid - gives vinegar its sour taste

77 77 Amino  compounds with NH 2 = amines  amino acids, nucleic acids  NH 2 acts as base - can pick up a proton (H + ) from the surrounding solution (ionized)  glycine (has amine and carboxyl groups) – replace an H with an R group to get an amino acid  under cellular conditions

78 78 Sulfhydryl  compounds with SH = thiols  2 sulfhydryl groups can interact to help stabilize protein structure (S-S, disulfide bonds)

79 79 Phosphate compounds called organic phosphates Acidic – up to 2 negative charges when H + dissociates Links nucleotides in nucleic acids Energy-carrier group in ATP

80 Review



83 Do the functional groups make that much difference?  identical basic structure of male & female hormones  attachment of different functional groups  interact with different targets in the body

84 84 A Bit of Honey:  Bee keeping was used in Crete over 4000 years ago to allow for the collection of honey, a highly prized food having great value in ancient civilizations  Field bees gather the nectar, a sweet secretion in plant blossoms that contains fructose, glucose and sucrose  Some worker bees secrete beeswax - Hexacosanoic acid, C 26 H 52 O 2, and triacontanol, C 30 H 62 O


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