1. KRT-20111 Basic Biochemistry

2. KRT-20112 What is Biochemistry? Biochemistry is the study of the chemical interactions of living things. Biochemists study the structures and physical properties of biological molecules. –Often are involved in the manufacture of new drugs and medical treatments

3. KRT-20113 CHEMISTRY OF LIFE Elements: simplest form of a substance - cannot be broken down any further without changing what it isElements: simplest form of a substance - cannot be broken down any further without changing what it is Atom: the actual basic unit - composed of protons, neutrons, and electronsAtom: the actual basic unit - composed of protons, neutrons, and electrons

4. KRT-20114 THE ATOM Just like cells are the basic unit of life, the ATOM is the basic unit of matter.Just like cells are the basic unit of life, the ATOM is the basic unit of matter. They are very small. If placed side by side one million would stretch a distance of 1cm.They are very small. If placed side by side one million would stretch a distance of 1cm. The atom is made up of 3 particles.The atom is made up of 3 particles. ParticleCharge PROTON PROTON+ NEUTRONNEUTRAL ELECTRON-

5. KRT-20115 Electrons are not present within the atom, instead THEY REVOLVE AROUND THE NUCELUS OF THE ATOM & FORM THE ELECTRON CLOUDElectrons are not present within the atom, instead THEY REVOLVE AROUND THE NUCELUS OF THE ATOM & FORM THE ELECTRON CLOUD Draw a helium atom. Indicate where the protons, neutrons and electrons are.Draw a helium atom. Indicate where the protons, neutrons and electrons are. ++ - - PROTONS NEUTRONS ELECTRONS ATOMIC # = 2 (PROTONS) ATOMIC MASS = 4 (PROTONS & NEUTRONS)

6. KRT-20116 ISOTOPES atoms of the same element that HAVE A DIFFERENT NUMBER OF NEUTRONSatoms of the same element that HAVE A DIFFERENT NUMBER OF NEUTRONS Some isotopes are radioactive. This means that their nuclei is unstable and will break down at a CONSTANT RATE over time.Some isotopes are radioactive. This means that their nuclei is unstable and will break down at a CONSTANT RATE over time. There are several practical uses for radioactive isotopes:There are several practical uses for radioactive isotopes: 1.CARBON DATING 2.TRACERS 3.KILL BACTERIA / CANCER CELLS

7. KRT-20117 COMPOUNDS a substance formed by the chemical combination of 2 or more elements in definite proportionsa substance formed by the chemical combination of 2 or more elements in definite proportions –Ex: water, salt, glucose, carbon dioxide

8. KRT-20118 The cell is a COMPLEX CHEMICAL FACTORY containing some of the same elements found in the nonliving environment.The cell is a COMPLEX CHEMICAL FACTORY containing some of the same elements found in the nonliving environment. carbon (C), hydrogen (H), oxygen (O), and nitrogen (N) are present in the greatest percentagescarbon (C), hydrogen (H), oxygen (O), and nitrogen (N) are present in the greatest percentages

9. KRT-20119 TWO TYPES OF COMPOUNDS Organic - Contain C, H, and O in some ratio (usually referred to as chemicals of life)Organic - Contain C, H, and O in some ratio (usually referred to as chemicals of life) –Carbohydrates, Proteins, Lipids, Nucleic Acids Inorganic - usually "support" life - no specific ratio of C, H, and OInorganic - usually "support" life - no specific ratio of C, H, and O –Water (H2O), Carbon Dioxide (CO2)

10. KRT-201110 CHEMICAL BONDS Chemical bonds hold the atoms in a molecule together.Chemical bonds hold the atoms in a molecule together. There are 2 types of chemical bonds IONIC and COVALENTThere are 2 types of chemical bonds IONIC and COVALENT

11. KRT-201111 IONIC BONDS Occur when 1 or more electrons are TRANSFERRED from one atom to another.Occur when 1 or more electrons are TRANSFERRED from one atom to another. When an atom loses an electron it is a POSITIVE charge.When an atom loses an electron it is a POSITIVE charge. When an atom gains an electron it is a NEGATIVE chargeWhen an atom gains an electron it is a NEGATIVE charge These newly charged atoms are now called IONSThese newly charged atoms are now called IONS –Example: NaCl (SALT)

12. KRT-201112

13. KRT-201113 COVALENT BONDS Occur when electrons are SHARED by atoms.Occur when electrons are SHARED by atoms. These new structures that result from covalent bonds are called MOLECULESThese new structures that result from covalent bonds are called MOLECULES ** In general, the more chemical bonds a molecule has the more energy it contains** In general, the more chemical bonds a molecule has the more energy it contains SHARING IS CARING!

14. KRT-201114 MIXTURES Water is not always pure. It is often found as part of a mixture.Water is not always pure. It is often found as part of a mixture. A mixture is a material composed of TWO OR MORE ELEMENTS OR COMPOUNDS THAT ARE PHYSICALLY MIXEDA mixture is a material composed of TWO OR MORE ELEMENTS OR COMPOUNDS THAT ARE PHYSICALLY MIXED –Ex: salt & pepper mixed, sugar and sand – can be easily separated

15. KRT-201115 SOLUTION Two parts: SOLUTE – SUBSTANCE THAT IS BEING DISSOLVED (SUGAR / SALT)SOLUTE – SUBSTANCE THAT IS BEING DISSOLVED (SUGAR / SALT) SOLVENT - the substance in which the solute dissolvesSOLVENT - the substance in which the solute dissolves Materials that do not dissolve are known as SUSPENSIONS.Materials that do not dissolve are known as SUSPENSIONS. –Blood is the most common example of a suspension. –Cells & other particles remain in suspension.

16. KRT-201116 FORMULA The chemical symbols and numbers that compose a compound ("recipe")The chemical symbols and numbers that compose a compound ("recipe") Structural Formula – Line drawings of the compound that shows the elements in proportion and how they are bondedStructural Formula – Line drawings of the compound that shows the elements in proportion and how they are bonded Molecular Formula – the ACTUAL formula for a compoundMolecular Formula – the ACTUAL formula for a compound C2H6OC2H6OC2H6OC2H6O

17. KRT-201117 ACIDS & BASES Acids: always (almost) begin with "H" because of the excess of H+ ions (hydrogen)Acids: always (almost) begin with "H" because of the excess of H+ ions (hydrogen) –Ex: lemon juice (6), stomach acid (1.5), acid rain (4.5), normal rain (6) Facts about Acids Acids turn litmus paper BLUE and usually taste SOUR.Acids turn litmus paper BLUE and usually taste SOUR. You eat acids daily (coffee, vinegar, soda, spicy foods, etc…)You eat acids daily (coffee, vinegar, soda, spicy foods, etc…)

18. KRT-201118 ACIDS & BASES Bases: always (almost) end with -OH because of the excess of hydroxide ions (Oxygen & Hydrogen)Bases: always (almost) end with -OH because of the excess of hydroxide ions (Oxygen & Hydrogen) –EX: oven cleaner, bleach, ammonia, sea water, blood, pure water Facts about Bases Bases turn litmus BLUE.Bases turn litmus BLUE. Bases usually feel SLIPPERY to touch and taste BITTER.Bases usually feel SLIPPERY to touch and taste BITTER.

19. KRT-201119 Neutralization Reactions When an acid reacts with a base to produce a salt and water.When an acid reacts with a base to produce a salt and water.

20. KRT-201120 pH SCALE measures degree of substance alkalinity or aciditymeasures degree of substance alkalinity or acidity Ranges from 0 to 14Ranges from 0 to 14 0 – 5 strong acid0 – 5 strong acid 6-7 neutral6-7 neutral 8-14 strong base8-14 strong base

21. KRT-201121 The goal of the body is to maintain HOMEOSTASIS (neutrality) – to do this when pH is concerned, we add weak acids & bases to prevent sharp changes in pH.The goal of the body is to maintain HOMEOSTASIS (neutrality) – to do this when pH is concerned, we add weak acids & bases to prevent sharp changes in pH. These are called BUFFERSThese are called BUFFERS

22. KRT-201122 Elements in Living Organisms The most common elements found in living organisms include: –Carbon (C) –Oxygen (O) –Nitrogen (N) –Hydrogen (H) –Phosphorus (P) –Sulfur (S)

23. KRT-201123 Periodic Table of the Elements (excerpt)

24. KRT-201124 Biochemistry: where chemistry and biology meet head-on Living things require millions of chemical reactions within the body, just to survive. Metabolism = all the chemical reactions occurring in the body. Organic molecules: –usually associated with living things. –always contain CARBON. –are “large” molecules, with many atoms –always have covalent bonds (share electrons)

25. KRT-201125 Plant Metabolism

26. KRT-201126

27. KRT-201127 Primary Metabolites Primary metabolites are compounds that are commonly produced by all plants and that are directly used in plant growth and development. The main primary metabolites are carbohydrates,lipids, proteins, and nucleic acids.

28. KRT-201128

29. KRT-201129 Macromolecules of Cells Macro = large 4 types of macromolecules in cellular biology 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic Acids ( DNA & RNA)

30. KRT-201130 Macromolecule #1: Carbohydrates Sugars and groups of sugars Purposes: energy and structure Includes three types: –Monosaccharide (1 sugar – quick energy) –Disaccharide (2 sugars – short storage) –Polysaccharide (many sugars – energy long storage & form structures)

31. KRT-201131 Carbohydrates Carbohydrates are the sugars made up of glucose and its isomers Carbohydrates come in many different sizes: Monosaccharides made up of one sugar unit (glucose or fructose) Disaccharides made up of two sugar units (sucrose is a glucose and a fructose) Polysaccharides are polymers made up of more than two sugar units

32. KRT-201132 Monosaccharides (simple sugars) all have the formula C6 H12 O6all have the formula C6 H12 O6 all have a single ring structureall have a single ring structure –(glucose is an example)

33. KRT-201133 Disaccharides (double sugars) all have the formula C12 H22 O11all have the formula C12 H22 O11 sucrose (table sugar) is an examplesucrose (table sugar) is an example

34. KRT-201134

35. KRT-201135 Harvesting Sucrose Sugar Cane Maple Syrup

36. KRT-201136 Refining Sucrose

37. KRT-201137 Macromolecule #1: Carbohydrates Polysaccharide Examples: –Glycogen—glucose polymer stored for future energy needs. Found in liver, muscle and sperm, etc. –Cellulose—glucose polymer used to form fibers for plant structures. Humans can’t digest (fiber). Most abundant organic molecule. –Chitin—glucose polymer for exoskeletons of some crustaceans & insects.

38. KRT-201138 Polysaccharides Structural polysaccharides are used to support plants Storage polysaccharides are used to store energy for later use by the plant

39. KRT-201139 Structural Polysaccharides The most common structural polysaccharide in plants is cellulose. It makes up 40 to 60% of the cell wall. It is also the most common polymer on earth Cellulose is extremely strong due to its chemical organization. It is made of a long chain of beta-glucose molecules – 100 to 15,000 glucose molecules

40. KRT-201140

41. KRT-201141 CARBOHYDRATES Living things use carbohydrates as a key source of ENERGY!Living things use carbohydrates as a key source of ENERGY! Plants use carbohydrates for structure (CELLULOSE)Plants use carbohydrates for structure (CELLULOSE) –include sugars and complex carbohydrates (starches) –contain the elements carbon, hydrogen, and oxygen (the hydrogen is in a 2:1 ratio to oxygen)

42. KRT-201142 Polysaccharides Formed of three or more simple sugar unitsFormed of three or more simple sugar units Glycogen - animal starch stored in liver & musclesGlycogen - animal starch stored in liver & muscles Cellulose - indigestible in humans - forms cell wallsCellulose - indigestible in humans - forms cell walls Starches - used as energy storageStarches - used as energy storage

43. KRT-201143

44. KRT-201144 Cotton Boll – Pure Cellulose

45. KRT-201145 Polysaccharides

46. KRT-201146 Polysaccharides

47. KRT-201147 Gluey Polysaccharides Pectins are mainly polymers of galacturonic acid. Hemicelluloses are highly variable and are not related to cellulose. Grass hemicelluloses are high in xylose, with small amounts of arabinose, galactose, and urionic acids. But pea family (Fabaceae) are high in arabinose, galactose and urionic acid, but low in xylose. Some of the most interesting hemicelluloses are not actually used structurally, but rather are exuded from stems, leaves, roots, or fruits in a sticky mixture called a gum

48. KRT-201148 Pectin and Hemicellulose

49. KRT-201149 Gum Arabic from Acacia senegal

50. KRT-201150 Storage Polysaccharides The most important storage polysaccharides are amylose and amylopectin. Amylose is a long chain of alpha-glucose, several hundred to several thousand molecules long. Amylopectin is more complex, often made up of 50,000 molecules. These two polymers are both used in making starch grains. Most starch grains are about 20% amylose and 80% amylopectin, but this varies with the plant.

51. KRT-201151

52. KRT-201152 Inulin – another storage carbohydrate

53. KRT-201153 Jerusalem artichoke

54. KRT-201154 How are complex carbohydrates formed and broken down?

55. KRT-201155 Dehydration Synthesis Combining simple molecules to form a more complex one with the removal of waterCombining simple molecules to form a more complex one with the removal of water –ex. monosaccharide + monosaccharide ----> disaccharide + water –(C6H12O6 + C6H12O6 ----> C12H22O11 + H2O Polysaccharides are formed from repeated dehydration syntheses of waterPolysaccharides are formed from repeated dehydration syntheses of water –They are the stored extra sugars known as starch

56. KRT-201156

57. KRT-201157 Hydrolysis Addition of WATER to a compound to SPLIT it into smaller subunitsAddition of WATER to a compound to SPLIT it into smaller subunits –(also called chemical digestion) –ex. disaccharide + H2O ---> monosaccharide + monosaccharide C12 H22 O11 + H2 O ---> C6 H12 O6 + C6 H12 O6

58. KRT-201158

59. KRT-201159 Macromolecule #2: Lipids Insoluble in water (think oil & water) 4 types: –1-triglycerides (fats & oils) (long-term energy storage, insulation) –2-phospholipids (primary component of cell membrane) –3-steroids (cell signaling) cholesterol molecules modified to form sex hormones. (e.g. testosterone, estrogen, etc.) –4-waxes (protection, prevents water loss) Used mainly by plants, but also bees, some furry animals and humans.

60. KRT-201160 Triglycerides

61. KRT-201161 Phospholipids

62. KRT-201162 Steroids

63. KRT-201163 Waxes

64. KRT-201164 Lipids (Fats) Fats, oils, waxes, steroidsFats, oils, waxes, steroids Chiefly function in energy storage, protection, and insulationChiefly function in energy storage, protection, and insulation Contain carbon, hydrogen, and oxygen but the H:O is not in a 2:1 ratioContain carbon, hydrogen, and oxygen but the H:O is not in a 2:1 ratio Tend to be large molecules -- an example of a neutral lipid is belowTend to be large molecules -- an example of a neutral lipid is below

65. KRT-201165 Neutral lipids are formed from the union of one glycerol molecule and 3 fatty acidsNeutral lipids are formed from the union of one glycerol molecule and 3 fatty acids 3 fatty acids + glycerol ----> neutral fat (lipid)3 fatty acids + glycerol ----> neutral fat (lipid) Fats -- found chiefly in animalsFats -- found chiefly in animals Oils and waxes -- found chiefly in plantsOils and waxes -- found chiefly in plants Oils are liquid at room temperature, waxes are solidsOils are liquid at room temperature, waxes are solids Lipids along with proteins are key components of cell membranesLipids along with proteins are key components of cell membranes Steroids are special lipids used to build many reproductive hormones and cholesterolSteroids are special lipids used to build many reproductive hormones and cholesterol

66. KRT-201166 Oils Oils occur in all parts of a plant, but are most common in seeds. Some seeds have so much oil that it can be commercially harvested. The most commonly used oils are cotton, sesame, safflower, sunflower, olive, coconut, peanut, corn, castor bean, and soybean oils. The most common seed oil fatty acids are oleic acid (one double bond), linoleic acid (two double bonds), and linolenic acid (three double bonds). Linoleic and linolenic are essential fatty acids – we can’t make them ourselves.

67. KRT-201167 Olive Oil

68. KRT-201168 Waxes Waxes are complex mixtures of fatty acids linked to long-chain alcohols. Waxes comprise the outermost layer of leaves, fruits, and herbaceous stems and are called EPICUTICULAR waxes. Waxes embedded in the cuticle of the plant are cuticular waxes. Cutin is another wax in the cuticle and it makes up most of the cuticle. Suberin is a similar wax that is found in cork cells in bark and in plant roots. Both help prevent water loss by the plant. Structures of waxes vary depending on which plant produced them. Waxes are usually harder and more water repellant than other fats.

69. KRT-201169 Bayberry Wax

70. KRT-201170 Jojoba Wax

71. KRT-201171 Macromolecule #3: Proteins The building blocks of proteins are AMINO ACIDS. There are only 20 types of Amino Acids. There are millions of different proteins, and they are all built from different combinations of the 20 amino acids. Amino acids join together to form peptides, polypeptides, and polypeptide chains.

72. KRT-201172 Macromolecule #3: Proteins Probably the most complicated of all biological molecules. Serve the most varied purposes, including: Support structural proteins (e.g., keratin, collagen) Enzymes speed up chemical reactions Transport cell membranes channels, transporters in blood (e.g., Hemoglobin) Defense antibodies of the immune system Hormones cell signaling (e.g., insulin) Motion contractile proteins (e.g., actin, myosin)

73. KRT-201173 Collagen

74. KRT-201174 Antibodies

75. KRT-201175 Cellular Transport

76. KRT-201176 actin & myosin fibers in muscles Motion

77. KRT-201177 PROTEINS contain the elements carbon, hydrogen, oxygen, and nitrogencontain the elements carbon, hydrogen, oxygen, and nitrogen composed of MANY amino acid subunitscomposed of MANY amino acid subunits It is the arrangement of the amino acid that forms the primary structure of proteins.It is the arrangement of the amino acid that forms the primary structure of proteins. The basic amino acid form has a carboxyl group on one end, a methyl group that only has one hydrogen in the middle, and a amino group on the other end.The basic amino acid form has a carboxyl group on one end, a methyl group that only has one hydrogen in the middle, and a amino group on the other end. Attached to the methyl group is a R group.Attached to the methyl group is a R group.

78. KRT-201178 AN R GROUP IS ANY GROUP OF ATOMS – THIS CHANGES THE PROPERTIES OF THE PROTEIN!

79. KRT-201179 FUNCTIONAL GROUPS There are certain groups of atoms that are frequently attached to the organic molecules we will be studying, and these are called functional groups.There are certain groups of atoms that are frequently attached to the organic molecules we will be studying, and these are called functional groups. These are things like hydroxyl groups which form alcohols, carbonyl groups which form aldehydes or ketones, carboxyl groups which form carboxylic acids, and amino groups which form amines.These are things like hydroxyl groups which form alcohols, carbonyl groups which form aldehydes or ketones, carboxyl groups which form carboxylic acids, and amino groups which form amines.

80. KRT-201180

81. KRT-201181 Major Protein Functions Growth and repairGrowth and repair EnergyEnergy Buffer -- helps keep body pH constantBuffer -- helps keep body pH constant

82. KRT-201182 Dipeptide formed from two amino acid subunitsformed from two amino acid subunits Formed by the process of Dehydration SynthesisFormed by the process of Dehydration Synthesis amino acid + amino acid ----- dipeptide + wateramino acid + amino acid ----- dipeptide + water

83. KRT-201183 Hydrolysis of a dipeptide Breaking down of a dipeptide into amino acidsBreaking down of a dipeptide into amino acids dipeptide + H2O ---> aminoacid + amino aciddipeptide + H2O ---> aminoacid + amino acid

84. KRT-201184 Polypeptide (protein) composed of three or more amino acids linked by synthesis reactionscomposed of three or more amino acids linked by synthesis reactions Examples of proteins include insulin, hemoglobin, and enzymes.Examples of proteins include insulin, hemoglobin, and enzymes. ** There are an extremely large number of different proteins.** There are an extremely large number of different proteins. The bases for variability include differences in the number, kinds and sequences of amino acids in the proteinsThe bases for variability include differences in the number, kinds and sequences of amino acids in the proteins

85. KRT-201185 Proteins Proteins make up most of the remaining biomass of living plant cells. A protein consists of one or more polypeptides made up of amino acids. Plants make amino acids from the products of photosynthesis through a very complex process involving the acquisition of N, usually in the form of NH 4, and involving the use of large amounts of energy, in the form of ATP and NADPH.

86. KRT-201186

87. KRT-201187 Structural Proteins Structural proteins make up 2 to 10% of the cell wall in plants. Expansins help increase the surface area of cell walls. Extensins help protect or repair damaged cell walls. The plant cell membrane is about 50% structural proteins.

88. KRT-201188 Storage Proteins Storage proteins are used mostly in seeds and are used as source of nutrition for the early development of seedlings. Storage proteins used in seeds vary considerably between plant species. Corn produces a storage protein called ZEIN. Wheat produces a storage protein called GLIADIN

89. KRT-201189 Macromolecule #4: Nucleic Acids Nucleotides: building blocks of nucleic acids. –Each nucleotide contains (a) phosphate molecule, (b) nitrogenous base, and (c) 5-carbon sugar Several types of nucleic acids, including: –DNA: deoxyribonucleic acid Genetic material, double stranded helix –RNA: ribonucleic acid Genetic material, single stranded –ATP: adenosine triphosphate High energy compound

90. KRT-201190 The 4th type of biochemical macromolecules are the NUCLEIC ACIDS The types of Nucleic Acids we will study are: –DNA (DeoxyriboNucleic Acid) –RNA (RiboNucleic Acid)

91. KRT-201191 NUCLEIC ACIDS THERE ARE 2 TYPES OF NUCLEIC ACIDS DNA RNA

92. KRT-201192 DNA

93. KRT-201193 “DNA” is short for DeoxyriboNucleic Acid Now you know why they just call it DNA!

94. KRT-201194 Nucleic Acids 1)DNA Is our genetic material. Chromosomes are made of DNA. Chromosomes contain the “recipes” to make proteins for your body. 2)RNA Reads the DNA “protein recipes” and makes the proteins for your body.

95. KRT-201195 NUCLEIC ACIDS Nucleic Acids are chains (polymers) made of monomers. Nucleic acids are made up of Which are nitrogen bases…something we will learn more about when we study DNA

96. KRT-201196 The shape of a nucleic acid is:

97. KRT-201197 Nucleotide Structure

98. KRT-201198 Nucleic Acids Each nucleic acid is made up of… THINK: “PONCH”

99. KRT-201199 Nucleic acids The nucleic acids in food are not considered a substance that the body uses to gain energy.

100. KRT-2011100 ENERGYSo… BIG 4 MACROMOLECULES Number of Calories it provides/g Carbohydrates4 Proteins4 Lipids9 Nucleic Acids0 TEST: TEST: Are you smart? If you eat a sandwhich with 46 grams of carbs and 24 grams of protein and 10 grams of fat, how much energy will you gain?

101. KRT-2011101 NUCLEIC ACIDS in all cellsin all cells composed of NUCLEOTIDEScomposed of NUCLEOTIDES store & transmit heredity/genetic informationstore & transmit heredity/genetic information Nucleotides consist of 3 parts:Nucleotides consist of 3 parts: 1. 5-Carbon Sugar1. 5-Carbon Sugar 2. Phosphate Group2. Phosphate Group 3. Nitrogenous Base3. Nitrogenous Base

102. KRT-2011102

103. KRT-2011103 Nucleic Acids The most complex biological polymers are the nucleic acids that make up RNA and DNA. The basic content of bases (adenine, thymine, guanine and cytosine) are similar in all plants

104. KRT-2011104 DNA (deoxyribonucleic acid) contains the genetic code of instructions that direct a cell's behavior through the synthesis of proteinscontains the genetic code of instructions that direct a cell's behavior through the synthesis of proteins found in the chromosomes of the nucleus (and a few other organelles)found in the chromosomes of the nucleus (and a few other organelles)

105. KRT-2011105 RNA (ribonucleic acid) directs cellular protein synthesisdirects cellular protein synthesis found in ribosomes & nucleolifound in ribosomes & nucleoli

106. KRT-2011106 CHEMICAL REACTIONS a process that changes one set of chemicals into another set of chemicalsa process that changes one set of chemicals into another set of chemicals REACTANTS – elements or compounds that enter into a chemical reactionREACTANTS – elements or compounds that enter into a chemical reaction PRODUCTS – elements or compounds that are produced in a chemical reactionPRODUCTS – elements or compounds that are produced in a chemical reaction Chemical reactions always involve the breaking of bonds in reactants and the formation of new bonds in products.Chemical reactions always involve the breaking of bonds in reactants and the formation of new bonds in products.

107. KRT-2011107 In a reaction, energy is either TAKEN IN (ENDOTHERMIC) or GIVEN OFF (EXOTHERMIC)In a reaction, energy is either TAKEN IN (ENDOTHERMIC) or GIVEN OFF (EXOTHERMIC) Can you think of an everyday example of each type of reaction?Can you think of an everyday example of each type of reaction?

108. KRT-2011108 Enzymes and Enzyme Action catalyst: inorganic or organic substance which speeds up the rate of a chemical reaction without entering the reaction itselfcatalyst: inorganic or organic substance which speeds up the rate of a chemical reaction without entering the reaction itself enzymes: organic catalysts made of proteinenzymes: organic catalysts made of protein most enzyme names end in -asemost enzyme names end in -ase enzymes lower the energy needed to start a chemical reaction. (activation energy)enzymes lower the energy needed to start a chemical reaction. (activation energy) begin to be destroyed above 45øC. (above this temperature all proteins begin to be destroyed)begin to be destroyed above 45øC. (above this temperature all proteins begin to be destroyed)

109. KRT-2011109 It is thought that, in order for an enzyme to affect the rate of a reaction, the following events must take place. 1.The enzyme must form a temporary association with the substance or substances whose reaction rate it affects. These substances are known as substrates. 2.The association between enzyme and substrate is thought to form a close physical association between the molecules and is called the enzyme-substrate complex. 3.While the enzyme-substrate complex is formed, enzyme action takes place. 4.Upon completion of the reaction, the enzyme and product(s) separate. The enzyme molecule is now available to form additional complexes.

110. KRT-2011110 Enzymes Enzymes catalyze biochemical reactions. Most proteins in living cells are enzymes. Pure enzymes that maintain their activity when removed from plants are commercially important to us.

111. KRT-2011111 Papaya – Papain and Chymopapain

112. KRT-2011112 Pineapple - Bromelain

113. KRT-2011113 How do enzymes work? substrate: molecules upon which an enzyme actssubstrate: molecules upon which an enzyme acts the enzyme is shaped so that it can only lock up with a specific substrate moleculethe enzyme is shaped so that it can only lock up with a specific substrate molecule enzyme enzyme substrate -------------> product

114. KRT-2011114 "Lock and Key Theory" each enzyme is specific for one and ONLY one substrate (one lock - one key)each enzyme is specific for one and ONLY one substrate (one lock - one key) this theory has many weaknesses, but it explains some basic things about enzyme function this theory has many weaknesses, but it explains some basic things about enzyme function

115. KRT-2011115 Factors Influencing Rate of Enzyme Action 1. pH - the optimum (best) in most living things is close to 7 (neutral) high or low pH levels usually slow enzyme activityhigh or low pH levels usually slow enzyme activity A few enzymes (such as gastric protease) work best at a pH of about 2.0A few enzymes (such as gastric protease) work best at a pH of about 2.0

116. KRT-2011116 2. Temperature - strongly influences enzyme activity optimum temperature for maximum enzyme function is usually about 35-40 C.optimum temperature for maximum enzyme function is usually about 35-40 C. reactions proceed slowly below optimal temperaturesreactions proceed slowly below optimal temperatures above 45 C most enzymes are denatured (change in their shape so the enzyme active site no longer fits with the substrate and the enzyme can't function)above 45 C most enzymes are denatured (change in their shape so the enzyme active site no longer fits with the substrate and the enzyme can't function)

117. KRT-2011117 3. Concentrations of Enzyme and Substrate ** When there is a fixed amount of enzyme and an excess of substrate molecules -- the rate of reaction will increase to a point and then level off.** When there is a fixed amount of enzyme and an excess of substrate molecules -- the rate of reaction will increase to a point and then level off.

118. KRT-2011118 Plant Secondary Metabolites Plants make a variety of less widely distributed compounds such as morphine, caffeine, nicotine, menthol, and rubber. These compounds are the products of secondary metabolism, which is the metabolism of chemicals that occurs irregularly or rarely among plants, and that have no known general metabolic role in plants. Secondary metabolites or secondary compounds are compounds that are not required for normal growth and development, and are not made through metabolic pathways common to all plants. Most plants have not been examined for secondary compounds and new compounds are discovered almost daily.

119. KRT-2011119 Plant Secondary Metabolites Secondary compounds are grouped into classes based on similar structures, biosynthetic pathways, or the kinds of plants that make them. The largest such classes are the alkaloids, terpenoids, and phenolics. Secondary compounds often occur in combination with one or more sugars. These combination molecules are known as glycosides. Usually the sugar is a glucose, galactose or rhamnose. But some plants have unique sugars. Apiose sugar is unique to parsley and its close relatives.

120. KRT-2011120 Functions of Secondary Compounds The most common roles for secondary compounds in plants are ecological roles that govern interactions between plants and other organisms. Many secondary compounds are brightly colored pigments like anthocyanin that color flowers red and blue. These attract pollinators and fruit and seed dispersers. Nicotine and other toxic compounds may protect the plant from herbivores and microbes. Other secondary compounds like rubber and tetrahydrocannabinil (THC) from cannabis plants have no known function in plants.

121. KRT-2011121 Alkaloids Alkaloids generally include alkaline substances that have nitrogen as part of a ring structure. More than 6500 alkaloids are known and are the largest class of secondary compounds. They are very common in certain plant families, especially: peas – Fabaceae sunflower – Asteraceae poppy – Papaveraceae tomato – Solanaceae dogbanes – Apocynaceae milkweeds - Asclepiadaceae citrus – Rutaceae.

122. KRT-2011122

123. KRT-2011123 Terpenoids Terpenoids are dimers and polymers of 5 carbon precursors called isoprene units (C 5 H 8 ). Terpenoids often evaporate from plants and contribute to the haze we see on hot sunny days. They are expensive to make; they often take 2% of the carbon fixed in photosynthesis; carbon that could otherwise be used for sugars.

124. KRT-2011124

125. KRT-2011125 Phenolics Compounds that contain a fully unsaturated six carbon ring linked to an oxygen are called phenolics. Salicylic acid (basic part of aspirin) is a simple phenol. Myristicin is a more complex phenol that provides the flavor of nutmeg. Flavonoids are complex phenolics. They are often sold in health food stores as supplements to vitamin C. The most commonly available flavonoid is rutin from buckwheat. Anthocyanins are a type of flavonoid that give flowers red and blue pigments.

126. KRT-2011126 More Phenolics Some phenolics form polymers. Tannins are astringent to the taste. They give dryness (astringency) to dry wines. They can also be used to tan leather. They often give water a tea-colored look. Tannins are common in pines and oaks. Lignin is a major structural component of wood. The exact structure of lignin is complex and not known.

127. KRT-2011127

128. KRT-2011128 Minor Secondary Metabolites Mustard oil glycosides are nitrogen-sulfur containing compounds that occur in cabbage, broccoli, horseradish, watercress and other members of the mustard family (Brassicaceae). They give the group its characteristic taste and odor. Cyanogenic glycosides occur in several families of plants, but are especially common in roses (Rosaceae) and peas (Fabaceae). They are sugar containing compounds that release cyanide gas when hydrolyzed. Cardiac glycosides effect vertebrate heart rate. Especially common in milkweeds Asclepiadaceae. The parsley/carrot family Apiaceae is noted for having aromatic and poisonous 17 carbon polyacetylenes, though a few species have alkaloids like Coniium.

129. KRT-2011129 Mustard Oil

130. KRT-2011130 THE BIG PICTURE Chemistry is essential for life…