Molecules of Life Chapter 22 Great Idea: A cell s major parts are constructed from a few simple molecular building blocks 1
Chapter Outline Organic Molecules Organic Chemistry Proteins: The Workhorses of Life Carbohydrates Lipids Minerals and Vitamins 2
Organic Molecules 3
Four Basic Characteristics Most molecules based on chemistry of carbon Organic molecules Life s molecules form from few elements H, O, C, N 97.5% of body weight Molecules composed of simple building blocks Arranged differently Shape determines behavior Determines ability for bonding 4
Chemical Shorthand No H atoms or bonds to H are shown C atoms are not shown explicitly Shorthand 5
iclicker Question Most molecules in living systems are based on the chemistry of: A nitrogen B carbon C phosphorus D sodium 6
iclicker Question Which four elements comprise 97.5% of our bodies weight? A P, S, Ca and Mg B Fe, H, O, Na C H, O, C, N 7
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Remember Abundance of Elements in Solar System C Relative Abundance of Elements in the Sun Log of Relative Abundance 12 10 8 6 4 2 0 H He Li Be C O Ne Mg Fe Si S N Ar Ca Al Na P Cl K Fe B 0 5 10 15 20 25 30 35 40 45 Atomic Number 9
Recall Covalent Bonds and Carbon C is a special case C - C C C C C C Valence electrons for C are four (one in each orbit of the 2 nd shell) C C: single covalent bond (one orbit; two atoms) C C C: two covalent bonds; two orbits; three atoms 10
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Principles of Carbon Chemistry: Functional Groups Features of C macromolecules Carbon skeleton (chains, branches, rings) Groups of atoms attached to carbon skeleton - functional groups Hydroxyl (OH) Amino (NH 2 ) Phosphate (P) C C C OH C 12
Principle of Polymers Small molecules joined together to form large molecules up to 1,000 s of carbon atoms (macromolecules) Array of combinations, each with its own unique chemistry Principle of hierarchy theory and emergent properties 13
Simple to Complex Polymers of Carbon Methane - 1 C atom Ethane 2 C atoms Fullerene 60 + C atoms (Buckyballs) 14
Complex Carbon Polymers nicotene caffeine aspirin Taxol chemotherapy drug 15
Hierarchy Theory and Emergent Properties Number of macromolecules, each with its own chemistry Carbon Skeletons (e.g., branch, chains, etc. Functional Groups (e.g., OH, NH2, etc.) Carbon Atoms 16
Principle of Polymers In living systems, polymers of carbon result in four major classes of macromolecules Carbohydrates Proteins Nucleic acids Lipids Potential diversity of carbon polymers 17
Hydrocarbons Carbon compounds with only two elements (carbon and hydrogen) Most simple compound: methane (CH 4 ) H H C H H 18
Hydrocarbons: C to C Bonding C to C bond can be single bond (C-C) Ethane C to C bond can be double bond (C = C) Ethene or ethylene C to C bond can be triple bond (C = C) Ethyne Saturated/unsaturated 19
Hydrocarbons Alkanes (C C bonds only) Methane (C 1 H 4 ) Natural gas Ethane (C 2 H 6 ) Propane (C 3 H 8 ) Propane gas Butane (C 4 H 10 ) Pentane (C 5 H 12 ) Octane(C 8 H 18 ) Gasoline Decane(C 10 H 22 ) Pattern: C n H 2n + 2 ) Triple bond (C = C) Double bond (C = C) Aromatics (cyclic C atoms/aromatics) C 6 H 6 20
Aromatic Hydrocarbons 21
Question There are millions of organic compounds but only a few thousand inorganic compounds because? A. Organic compounds are formed by living critters B. There is more C on the Earth s surface than most other elements C. Atoms of elements other than C never combine with themselves D. C atoms combine with up to four other atoms, including other C atoms 22
Functionality of Hydrocarbons Carbon skeleton Functional groups (e.g., OH) 23
Organic and Biochemistry Keys: Structure of basic unit (monomer) Polymer structure (macromolecule) Functional group (e.g., OH, PO 3 or NH 2 ) Types of carbon polymers in living systems Carbohydrates Lipids Proteins Nucleic acids 24
Biochemistry Carbohydrates Monomer: monosaccharide (glucose or C 6 H 12 O 6 ) Polymer: polysaccharide Functional unit: hydroxyl or OH - Proteins Monomer: amino acid (peptide) Polymer: polypeptide and protein Functional unit: amine or NH 2 Nucleic Acids Monomer: nucleotide Polymer: polynucleotide - DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) Functional units: organic N base, carbohydrate, and phosphate Lipids Monomer: fatty acid + glycerol unit Polymer: fats, phospholipids and steroids Functional unit: glycerol (3 OH- groups) 25
iclicker Question Fatty acids and glycerols are part of A Carbohydrates B Proteins C Nucleic Acids D Lipids 26
iclicker Question The monomer monosaccharide is what type of molecular polymer? A Carbohydrate B Protein C Nucleic Acid D Lipid 27
iclicker Question Amino acids are portions of A Carbohydrates B Proteins C Nucleic Acids D Lipids 28
iclicker Question Nucleotides are portions of A Carbohydrate B Protein C Nucleic Acid D Lipid 29
Carbohydrates 30
Carbohydrates Structure C, H, O Simplest Sugars C n H 2n O n Monosaccharides Polysaccharide Starches Cellulose 31
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Carbohydrates Keys Monosaccharide or Glucose (C 6 H 12 O 6 ) Functional unit: hydroxyl or OH- 33
Monosaccharides 34
Polysaccharide: Glycogen 35
iclicker Question True or False: Starch and cellulose are both polymers of glucose. A True B False 36
iclicker Question Individual sugar molecules are called: A glucoses B starches C monosaccharides 37
iclicker Question The general chemical formula for sugar is: A NaCl B C n H 2n O n C C n H 2n+2 D C 20 H 38 S 2 N 4 38
Proteins: The Workhorses of Life 39
Amino Acids: The Building Blocks of Proteins Amino Acid Carboxyl group Amino group Carbon atom Side group 40
Amino Acids: The Building Blocks of Proteins Side Group Makes amino acid unique 41
Amino Acids cont. Bonding Two amino acids H bonds with OH Forms H 2 O Forms peptide bond Polypeptide chain Protein Large molecule Chain of amino acids Only 20 amino acids in living organisms 42
The Structure of Proteins 43
Enzymes (protein catalysts) Enzymes Specific shape & structure Facilitates bonding 44
Enzymes 45
How Most Drugs Work Blocking enzymes Block active site Molecules cannot bond Reaction does not take place Shape of molecules Block membrane transport Block neurotransmitters 46
Proteins Keys Amino acid (monomer) Polypeptide (polymer) Functional unit: amine or NH 2 Polypeptide bond serine lysine arginine tryptophan glutamic acid etc. 47
Proteins: Linear Structure 48
Proteins: Linear Structure 49
Protein Conformation (1 and 2 nd ) 50
Protein Conformation (3 rd & 4 rd ) 51
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iclicker Question Proteins are made up of strings of basic building blocks called: A amino acids B monosaccharides C nucleotides 54
iclicker Question How many different amino acids appear in the proteins of living systems on Earth? A 10 B 20 C 50 D 200 55
iclicker Question The exact sequence of amino acids that go into a protein is called its: A primary structure B secondary structure C tertiary structure D quaternary structure 56
iclicker Question In general, meat and dairy products supply low-quality proteins, while plant product supply high-quality proteins. A True B False 57
iclicker Question Of the 20 amino acids, how many are essential amino acids for human adults? A 8 B 12 C 17 D 20 58
iclicker Question Shapes taken by the string of amino acids of a protein, such as a long helix or a sphere, are called its: A primary structure B secondary structure C tertiary structure D quaternary structure 59
iclicker Question Silk, hair, and fingernails are made of: A proteins B lipids C carbohydrates 60
Nucleic Acids Keys Nucleotides Functional units: organic N base, carbohydrate, and phosphate 61
Nucleic Acids as Polymers: DNA Double Helix 62
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Lipids 64
Lipids Lipids Insoluble in water Role of lipids Cell membranes Store energy Phospholipids Make up cell membrane 65
Saturated C is fully bonded Basis of cholesterol Unsaturated Monounsaturated Polyunsaturated hydrogenation Saturated and Unsaturated Fats 66
Cell Membranes Cell membrane Hydrophilic Hydrophobic 67
Biochemistry: Lipids Keys Fatty acids C 16-18 Functional unit: glycerol (3 OH- groups) 68
Saturated Fats 69
Unsaturated Fats 70
iclicker Question Fatty acids and glycerols are part of A Carbohydrates B Proteins C Nucleic Acids D Lipids 71
iclicker Question Saturated fats have no double bonds. A True B False 72
iclicker Question The monomer monosaccharide is what type of molecular polymer? A Carbohydrate B Protein C Nucleic Acid D Lipid 73
iclicker Question Amino acids are portions of A Carbohydrates B Proteins C Nucleic Acids D Lipids 74
iclicker Question Nucleotides are portions of A Carbohydrate B Protein C Nucleic Acid D Lipid 75
Biochemistry Summary Carbohydrates Monomer: monosaccharide (glucose or C 6 H 12 O 6 ) Polymer: polysaccharide Functional unit: hydroxyl or OH - Proteins Monomer: amino acid (peptide) Polymer: polypeptide and protein Functional unit: amine or NH 2 Nucleic Acids Monomer: nucleotide Polymer: polynucleotide - DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) Functional units: organic N base, carbohydrate, and phosphate Lipids Monomer: fatty acid + glycerol unit Polymer: fats, phospholipids and steroids Functional unit: glycerol (3 OH- groups) 76
Carbon Metabolism Biosynthesis (Anabolism) CO 2 + H 2 O + Energy CH 2 O + O 2 (light) (C - C Bonds) Catabolism CH 2 O + O 2 CO 2 + H 2 O + Energy (C - C Bonds) (heat + chemical energy ATP) Key is the C-C covalent bonding, which in turn is determined by electrons in the valence state, which in turn is underpinned by energy of electrons in their respective shells (storage and processing of energy via the making and breaking of C-C bonds) 77
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Granola Bar and the Carbon Atom The energy of a granola bar is a function of multiple excited electrons being kicked to a higher quantum level in a chlorophyll molecule; subsequently, that potential energy is snatched and stored chemically in a carbohydrate molecule. When you digest the carbohydrate polymer and break the covalent bonds, the potential energy of the electron in an elevated state is released as heat/chemical energy in metabolism. 79
iclicker Question The chemical reactivity of organic carbon compounds is a function of the reactivity of the. A Carbon to carbon double bond (C = C) B Carbon to carbon triple bond (C = C) C Carbon to carbon single bond (C C) D Functional groups bond to the carbon atom E Reactivity of the covalent bonds between carbon atoms 80
Hierarchy in Biochemistry Protein Polypeptide Amino Acid Carbon Skeleton + Amine group (NH 2 ) 81
Minerals and Vitamins 82
Minerals Minerals All chemical elements except C, H, N, O Example Calcium 2% of weight 83
Vitamins Vitamins Organic molecules Must be taken in with food Except vitamin D Water soluble Vitamins B & C Fat soluble Vitamins A, D, E, & K Function Assist enzymes 84
SUMMARY Carbon is unique in its chemistry Unusual behavior of carbon results in an huge array of simple to complex molecules Life as we know it is hard to imagine without carbon behaving as a polymer The chemistry of carbon is a case study of the principle of hierarchy theory and emergent properties Carbon metabolism is the currency by which energy is processed, stored and used Weak chemical bonds (covalent carbon bonds) play a critical role in the chemistry of life 85
iclicker Question Which vitamins are water soluble? A B and C B A, D, E, and K C F, G, and H 86
iclicker Question The information in this chapter influences me in terms of eating a healthier diet. A True B False 87