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1 Biochemistry of Cells
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2 Uses of Organic Molecules Americans consume an average of 140 pounds of sugar per person per year Cellulose, found in plant cell walls, is the most abundant organic compound on Earth
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3 Uses of Organic Molecules A typical cell in your body has about 2 meters of DNA A typical cow produces over 200 pounds of methane gas each year
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4 Water About 60-90 percent of an organism is water Water is used in most reactions in the body Water is called the universal solvent
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5 Water Properties Polarity Cohesiveness Adhesiveness Surface Tension
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6 Carbon-based Molecules Although a cell is mostly water, the rest of the cell consists mostly of carbon-based molecules Organic chemistry is the study of carbon compounds
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7 Carbon is a Versatile Atom It has four electrons in an outer shell that holds eight Carbon can share its electrons with other atoms to form up to four covalent bonds
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8 Hydrocarbons The simplest carbon compounds … Contain only carbon & hydrogen atoms
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9 Carbon can use its bonds to:: Attach to other carbons Form an endless diversity of carbon skeletons
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10 Large Hydrocarbons: Are the main molecules in the gasoline we burn in our cars The hydrocarbons of fat molecules provide energy for our bodies
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11 Shape of Organic Molecules Each type of organic molecule has a unique three-dimensional shape The shape determines its function in an organism
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12 Functional Groups are: Groups of atoms that give properties to the compounds to which they attach Gained Electrons Lost Electrons
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13 Common Functional Groups
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14 Giant Molecules - Polymers Large molecules are called polymers Polymers are built from smaller molecules called monomers Biologists call them macromolecules
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15 Examples of Polymers Proteins Lipids Carbohydrates Nucleic Acids
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16 Most Macromolecules are Polymers Polymers are made by stringing together many smaller molecules called monomers Nucleic Acid Monomer
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17 Linking Monomers Cells link monomers by a process called dehydration synthesis (removing a molecule of water) This process joins two sugar monomers to make a double sugar Remove H Remove OH H 2 O Forms
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18 Breaking Down Polymers Cells break down macromolecules by a process called hydrolysis (adding a molecule of water) Water added to split a double sugar
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19 Macromolecules in Organisms There are four categories of large molecules in cells: Carbohydrates Lipids Proteins Nucleic Acids
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20 Carbohydrates Carbohydrates include: Small sugar molecules in soft drinks Long starch molecules in pasta and potatoes
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21 Carbohydrates Small sugar moleculeslarge sugar molecules Small sugar molecules to large sugar molecules.Examples: A.monosaccharide B.disaccharide C.polysaccharide
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22 Carbohydrates Monosaccharide: one sugar unit Examples:glucose ( Examples:glucose (C 6 H 12 O 6 )deoxyriboseriboseFructoseGalactose glucose
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23 Monosaccharides: Called simple sugars Include glucose, fructose, & galactose Have the same chemical, but different structural formulas C 6 H 12 O 6
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24 Monosaccharides Glucose is found in sports drinks Fructose is found in fruits Honey contains both glucose & fructose Galactose is called “milk sugar”
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25 Isomers Glucose & fructose are isomers because they’re structures are different, but their chemical formulas are the same
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26 Rings In aqueous (watery) solutions, monosaccharides form ring structures
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27 Cellular Fuel Monosaccharides are the main fuel that cells use for cellular work ATP
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28 Disaccharides A disaccharide is a double sugar They’re made by joining two monosaccharides Involves removing a water molecule (dehydration)
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29 Disaccharides Common disaccharides include: Sucrose (table sugar) Lactose (Milk Sugar) Maltose (Grain sugar )
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30 Disaccharides Sucrose is composed of glucose + fructose Maltose is composed of 2 glucose molecules Lactose is made of galactose + glucose GLUCOSE
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31 Carbohydrates Disaccharide: two sugar unit Examples: Sucrose (glucose+fructose) Lactose (glucose+galactose) Maltose (glucose+glucose) glucoseglucose
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32 Polysaccharides Complex carbohydrates Composed of many sugar monomers linked together Polymers of monosaccharide chains
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33 Examples of Polysaccharides Starch Glycogen Cellulose Glucose Monomer
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34 Starch Starch is an example of a polysaccharide in plants Plant cells store starch for energy Potatoes and grains are major sources of starch in the human diet
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35 Glycogen Glycogen is an example of a polysaccharide in animals Animals store excess sugar in the form of glycogen (in muscles and liver) Glycogen is similar in structure to starch
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36 Cellulose Cellulose is the most abundant organic compound on Earth It forms cable-like fibrils in the tough walls that enclose plants It is a major component of wood It is also known as dietary fiber
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37 Cellulose SUGARS
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38 Dietary Cellulose Most animals cannot derive nutrition from fiber They have bacteria in their digestive tracts that can break down cellulose
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39 Carbohydrates Polysaccharide: many sugar units Examples:starch (bread, potatoes) glycogen (beef muscle) cellulose (lettuce, corn) glucoseglucose glucoseglucose glucoseglucose glucoseglucose cellulose
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40 Sugars in Water Simple sugars and double sugars dissolve readily in water They are hydrophilic, or “water- loving” WATER MOLECULE SUGAR MOLECULE
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41 Lipids Lipids are hydrophobic –”water fearing” Includes fats, waxes, steroids, & oils Do NOT mix with water FAT MOLECULE
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42 Function of Lipids Fats store energy, help to insulate the body, and cushion and protect organs
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43 Types of Fatty Acids Unsaturated fatty acids have less than the maximum number of hydrogens bonded to the carbons (a double bond between carbons ) Saturated fatty acids have the maximum number of hydrogens bonded to the carbons (all single bonds between carbons )
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44 Types of Fatty Acids Single Bonds in Carbon chain Double bond in carbon chain
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45 Triglyceride Monomer of lipids Composed of Glycerol & 3 fatty acid chains Glycerol forms the “backbone” of the fat Organic Alcohol
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46 Triglyceride Glycerol Fatty Acid Chains
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48 Fats in Organisms Most animal fats have a high proportion of saturated fatty acids & exist as solids at room temperature (butter, margarine, shortening)
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49 Fats in Organisms Most plant oils tend to be low in saturated fatty acids & exist as liquids at room temperature (oils )
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50 Fats Dietary fat consists largely of the molecule triglyceride composed of glycerol and three fatty acid chains Glycerol Fatty Acid Chain Dehydration links the fatty acids to Glycerol
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54 Steroids The carbon skeleton of steroids is bent to form 4 fused rings Cholesterol is the “base steroid” from which your body produces other steroids Estrogen & testosterone are also steroids Cholesterol Testosterone Estrogen
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55 Synthetic Anabolic Steroids They are variants of testosterone Some athletes use them to build up their muscles quickly They can pose serious health risks
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56Lipids not soluble in water General term for compounds which are not soluble in water. are soluble in hydrophobic solvents Lipids are soluble in hydrophobic solvents. Remember:“stores the most energy” Remember: “stores the most energy” Examples:1. Fats 2. Phospholipids 3. Oils 4. Waxes 5. Steroid hormones 6. Triglycerides
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57 Proteins Proteins are polymers made of monomers called amino acids All proteins are made of 20 different amino acids linked in different orders Proteins are used to build cells, act as hormones & enzymes, and do much of the work in a cell
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58 Four Types of Proteins Structural Contractile Storage Transport
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59 Proteins (Polypeptides) peptide bonds polypeptides Amino acids (20 different kinds of aa) bonded together by peptide bonds (polypeptides). Six functions of proteins: 1.Storage:albumin (egg white) 2.Transport: hemoglobin 3.Regulatory:hormones 4.Movement:muscles 5.Structural:membranes, hair, nails 6.Enzymes:cellular reactions
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60 20 Amino Acid Monomers
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61 Structure of Amino Acids Amino acids have a central carbon with 4 things boded to it: Amino group -NH3 Carboxyl group -COOH Hydrogen -H Side group -R Amino group Carboxyl group R group Side groups Leucine -hydrophobic Serine-hydrophillic
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62 Linking Amino Acids Cells link amino acids together to make proteins The process is called dehydration synthesis Peptide bonds form to hold the amino acids together Carboxyl Amino Side Group Dehydration Synthesis Peptide Bond
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64 Proteins (Polypeptides) Four levels of protein structure: A.Primary Structure B.Secondary Structure C.Tertiary Structure D.Quaternary Structure
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66 Primary Protein Structure The primary structure is the specific sequence of amino acids in a protein Amino Acid
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67 Protein Structures Secondary protein structures occur when protein chains coil or fold When protein chains called polypeptides join together, the tertiary structure forms In the watery environment of a cell, proteins become globular in their quaternary structure
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71 Protein Structures Hydrogen bond Pleated sheet Amino acid (a) Primary structure Hydrogen bond Alpha helix (b) Secondary structure Polypeptide (single subunit) (c) Tertiary structure (d) Quaternary structure
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72 Denaturating Proteins Changes in temperature & pH can denature (unfold) a protein so it no longer works Cooking denatures protein in eggs Milk protein separates into curds & whey when it denatures
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74 Changing Amino Acid Sequence Substitution of one amino acid for another in hemoglobin causes sickle-cell disease (a) Normal red blood cellNormal hemoglobin 1 2 3 4 5 6 7... 146 (b) Sickled red blood cellSickle-cell hemoglobin 2 3 1 45 6 7... 146
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75 Proteins as Enzymes Many proteins act as biological catalysts or enzymes Thousands of different enzymes exist in the body Enzymes control the rate of chemical reactions by weakening bonds, thus lowering the amount of activation energy needed for the reaction
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76 Enzymes Their folded conformation creates an area known as the active site. Enzymes are globular proteins. The nature and arrangement of amino acids in the active site make it specific for only one type of substrate.
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77 Enzyme + Substrate = Product
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78 How the Enzyme Works Enzymes are reusable!!!
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79 Enzymes Free Energy Progress of the reaction Reactants Products Free energy of activation Without Enzyme With Enzyme
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81 Nucleic Acids Store hereditary information Contain information for making all the body’s proteins Two types exist --- DNA & RNA
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85 Nucleic Acids Nitrogenous base (A,G,C, or T) Phosphate group Thymine (T) Sugar (deoxyribose) Phosphate Base Suga r Nucleic acids are polymers of nucleotides Nucleotide
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86 Bases Each DNA nucleotide has one of the following bases: Thymine (T)Cytosine (C) Adenine (A)Guanine (G) – Adenine (A) – Guanine (G) – Thymine (T) – Cytosine (C)
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87 Nucleotide Monomers Form long chains called DNA Backbone Nucleotide Bases DNA strand Nucleotides are joined by sugars & phosphates on the side
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88 DNA Two strands of DNA join together to form a double helix Base pair Double helix
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89 DNA - double helix P P P O O O 1 2 3 4 5 5 3 3 5 P P P O O O 1 2 3 4 5 5 3 5 3 G C TA
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90 RNA – Ribonucleic Acid Ribose sugar has an extra –OH or hydroxyl group It has the base uracil (U) instead of thymine (T) Nitrogenous base (A,G,C, or U) Sugar (ribose) Phosphate group Uracil
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92 Websites to Explore http://www2.nl.edu/jste/biochem.htm Macromolecules of Life (animations) http://faculty.ccbcmd.edu/biotutorials/energy/adpan. html Hydrolysis of ATP molecule http://www.okc.cc.ok.us/biologylabs/index.htm OKC Biology Labs Online: Organic Molecules
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93 Summary of Key Concepts
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94 Nucleic Acids
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95 Macromolecules
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96 Macromolecules
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97 End http://www.bbc.co.uk/education/asguru/biology/02biologicalmolecules/index.shtml
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