Chapter 2. Basic Chemistry. Lecture Presentation by Patty Bostwick-Taylor Florence-Darlington Technical College Modified by Janice Alvarez, QRMHS

Transcription

1 Chapter 2 Basic Chemistry Lecture Presentation by Patty Bostwick-Taylor Florence-Darlington Technical College Modified by Janice Alvarez, QRMHS 2015 Pearson Education, Inc.

2 Matter and Energy Energy can change the position, physical composition, or temperature of matter What again is matter?

3 Matter and Energy Matter anything that occupies space and has mass Matter may exist as one of three states: Solid: definite shape and volume Liquid: definite volume; shape of container Gaseous: neither a definite shape nor volume

4 Matter and Energy Matter may be changed Physically Changes do not alter the basic nature of a substance Chemically Changes alter the chemical composition of a substance

5 Forms of Energy Chemical energy is stored in chemical bonds Electrical energy results from movement of charged particles Mechanical energy is energy directly involved in moving matter Radiant energy travels in waves (light/heat)

6 Matter and Energy Energy the ability to do work. Has no mass and does not take up space Kinetic energy: energy is doing work Potential energy: energy is inactive; stored Identify examples of potential and kinetic energy in these pictures.

7 Potential and kinetic energy Potential energy stored in food is converted to kinetic energy when we exercise.

8 Chemical Potential Energy (CPE)

9 Energy and Human Life ATP (adenosine triphosphate) traps the chemical energy of food in its bonds

10 Work Day Assignment Read Text p.24-26; take notes. Matter and Energy Workbook p Done Early? Read ahead: p27-30 WBp18-19

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12 Composition of Matter Atoms Building blocks of elements Atoms of elements differ from one another Atomic symbol is chemical shorthand for each element

13 Composition of Matter 96 percent of the body is made from four elements: Oxygen (O) Carbon (C) Hydrogen (H) Nitrogen (N)

14 Identifying Elements Atomic number equal to the number of protons that the atom contains Unique to atoms of a particular element Indirectly tells the number of electrons in an atom Atomic mass number sum of the protons and neutrons contained in an atom s nucleus

15 All Elements are Systematically Arranged on the Periodic Table of Elements

16 Chemistry of Life There are 92 naturally occurring elements. Of those 92 elements, 25 are essential to life!

17 Elements in Living Things CHOPKINS CaFe

18 Chemical Composition of the Human Body by Weight

19 Trace elements are critical for normal growth, development, and body function

20 Subatomic Particles An Element Consists of One Kind of Atom What makes up an atom? Protons + Neutrons Nucleus Electrons - Electrons determine an atom s chemical behavior

21 (a) Hydrogen (H) (1p + ; 0n 0 ; 1e ) (b) Helium (He) (2p + ; 2n 0 ; 2e ) (c) Lithium (Li) (3p + ; 4n 0 ; 3e ) KEY: Proton Neutron Electron Electrons determine an atom s chemical behavior 2015 Pearson Education, Inc.

22 Electron Shells An atom is considered stable when their outer shells are filled to capacity. Octet Rule

23 Periodic Table of Elements How do you calculate the number of neutrons?

24 Isotopes and Atomic Weight Atoms of the same element that differ in the number of neutrons are called isotopes. protons + neutrons in nucleus = atomic mass Isotopes are identified by their mass numbers. C-14

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26 Radioactivity Radioisotope Heavy isotope of certain atoms Tends to be unstable Decomposes to more stable isotope Radioactivity process of spontaneous atomic decay

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28 Molecules and Compounds Molecule two or more atoms of the same elements combined chemically Compound two or more atoms of different elements combined chemically to form a molecule of a compound ALL COMPOUNDS ARE MOLECULES BUT NOT ALL MOLECULES ARE COMPOUNDS!!!

29 Molecules and Compounds Properties of a compound differ from those of its atoms. Sodium (silvery metal) Chlorine (poisonous gas) Sodium chloride (table salt) 2015 Pearson Education, Inc.

30 Chemical Reactions Chemical reactions occur when atoms combine with or dissociate from other atoms Atoms are united by chemical bonds Atoms dissociate from other atoms when chemical bonds are broken 2015 Pearson Education, Inc.

31 Electrons and Bonding How atoms interact with each other depends on their valence electrons Bonding involves only interactions between electrons in the outer (valence) shell 2015 Pearson Education, Inc.

32 Electrons and Bonding Atoms with full valence shells do not form bonds (a) Chemically inert elements Outermost energy level (valence shell) complete He 2e Ne 8e 2e Helium (He) Neon (Ne) 2015 Pearson Education, Inc.

33 Reactive Elements Valence shell is incomplete Atoms will gain, lose, or share electrons to complete their outer shell Atoms reach stable state Bond formation = stable valence shell (b) Chemically reactive elements Outermost energy level (valence shell) incomplete H 1e Hydrogen (H) (1p + ; 0n 0 ; 1e ) O 2e 6e C 2e 4e Carbon (C) (6p + ; 6n 0 ; 6e ) 2e 8e1e Na Oxygen (O) (8p + ; 8n 0 ; 8e ) Sodium (Na) (11p + ; 12n 0 ; 11e ) 2015 Pearson Education, Inc.

34 Valence Electrons Determine Reactivity

35 Chemical Bonds 3 types of chemical bonds Ionic Bonds when one or more electrons are transferred from one atom to the other. Covalent Bonds when electrons are shared between atoms. Hydrogen Bonds weak electrical attraction between molecules.

36 Chemical Bonds Ionic bonds Electrons are completely transferred from one atom to another 2015 Pearson Education, Inc.

37 Chemical Bonds Ions: charged atoms Result from the loss or gain of electrons Anions - negatively charged ion (gained electron(s)) Cations - positively charged ion (lost electron(s)) Opposite charges attract form ionic bonds CATION ANION

38 Covalent Bond electrons are shared Methane CH 4 Water H 2 0

39 Chemical Bonds Covalent bonds Atoms become stable through shared electrons Electrons are shared in pairs Single covalent bonds share one pair of electrons Double covalent bonds share two pairs of electrons Reacting atoms Resulting molecules O O O O or Oxygen atom Oxygen atom (b) Formation of a double covalent bond Molecule of oxygen gas (O 2 ) 2015 Pearson Education, Inc.

40 Covalent Bonds Covalent bonds are either nonpolar or polar Nonpolar Electrons are shared equally between the atoms of the molecule Electrically neutral as a molecule Example: carbon dioxide Carbon dioxide (CO 2 ) 2015 Pearson Education, Inc.

41 Covalent Bonds Covalent bonds are either nonpolar or polar Polar Electrons are not shared equally between the atoms of the molecule Molecule has a positive and negative side, or pole Example: water δ δ + δ + Water (H 2 O) 2015 Pearson Education, Inc.

42 Hydrogen Bonds Weak chemical bonds Hydrogen is attracted to the negative portion of a polar molecule Responsible for the surface tension of water Important for forming intramolecular bonds, as in protein structure 2015 Pearson Education, Inc.

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44 Chemical Reactions

45 Chemical Reactions Review: Reactants and Products Reactants Product Reactant Products

46 Anabolic Chemical Reactions (a) Synthesis reactions Synthesis reaction (A B AB) Atoms or molecules combine Energy is absorbed in bonds Anabolic activities in the body Building polymers Growth Repair Smaller particles are bonded together to form larger, more complex molecules. Example Amino acids are joined together to form a protein molecule. Amino acid molecules Protein molecule 2015 Pearson Education, Inc.

47 Anabolic Chemical Reactions Dehydration synthesis Remove water to join two molecules Take out a hydrogen ion [H+] Take out a hydroxyl group [OH-] Monomers unite, and water is released Repeat to form polymers

48 Catabolic Chemical Reactions Decomposition reactions Decomposition reaction (AB A B) Molecule is broken down Chemical energy is released Catabolic activities in body Digestion Energy release Bonds are broken in larger molecules, resulting in smaller, less complex molecules. Example Glycogen is broken down to release glucose units. Glycogen 2015 Pearson Education, Inc. Glucose molecules

49 Catabolic Chemical Reactions Hydrolysis Polymers (large molecules) are broken into monomers Water molecules are added to break the bonds 2015 Pearson Education, Inc.

50 Patterns of Chemical Reactions Most chemical reactions are reversible Reversibility is indicated by a double arrow 2015 Pearson Education, Inc.

51 Biochemistry: Inorganic and Organic Molecules Essential to Life

52 Biochemistry: Essentials for Life Inorganic compounds Lack carbon Tend to be small, simple molecules Include water, salts, and some acids and bases Organic compounds Contain carbon All are large, covalently bonded molecules Include carbohydrates, lipids, proteins, and nucleic acids

53 Important Inorganic Compounds Water is the medium for chemical reactions in your body used to sustain life!

54 Important Inorganic Compounds Water Most abundant inorganic compound in the body Vital properties 1. High heat capacity 2. Polarity/solvent properties 3. Chemical reactivity 4. Cushioning Hydrogen Bonds!!

55 Water s Vital Properties 1. High heat capacity: Water absorbs and releases a large amount of heat before it changes temperature Prevents sudden changes in body temperature

56 How Water Moderates Temperature Water heated = hydrogen bonds break = water absorbs and stores large amounts of heat while warming up only a few degrees. Water cooled = hydrogen bonds form = release heat = water releases large amount of heat while the water temperature drops only slightly.

57 Water s Vital Properties: 2. Polarity / Solvent Properties Water as the Solvent of Life!! Solution a mixture of two or more substances where the molecules are evenly distributed (homogenous), forming an aqueous solution. Solute (salt) Solvent (water)

58 When Salt Dissolves in Water Water Molecule Water is considered the UNIVERSAL SOLVENT, dissolving other polar and ionic compounds

59 Water s Vital Properties 3. Chemical reactivity Water is an important reactant in chemical reactions Hydrolysis reactions require water helps digest food breaks down biological molecules

60 Important Inorganic Compounds 4. Cushioning Water serves a protective function cerebrospinal fluid protects the brain from trauma amniotic fluid protects a developing fetus

61 Important Inorganic Compounds Salts (electrolytes ions that conduct electrical charge) Contain cations and anions other than H + and OH Easily dissociates into ions when in water Vital to many body functions sodium and potassium ions aide nerve impulses

62 Important Inorganic Compounds Acids (Acidic) Release hydrogen ions (H + ) when dissolved in water Example: HCl H + Cl Are proton donors hydrogen ions are essentially just protons Strong acids ionize completely; liberate all protons Weak acids ionize incompletely

63 Important Inorganic Compounds Bases (Alkaline) Release hydroxyl ions (OH ) when dissolved in water Are proton acceptors Example: NaOH Na + + OH Strong bases seek hydrogen ions

64 Important Inorganic Compounds Neutralization reaction Acids and bases react to form water and a salt Example: NaOH HCl H 2 O NaCl

65 Acids, Bases and ph H 2 O (H + ) + (OH - ) Water (hydrogen ion) + (hydroxide ion) more (H+) ions more (OH-) ions

66 ph The Rules Measures relative concentration of hydrogen ions Based on the number of protons in a solution, expressed in terms of moles per liter Each successive change on the ph scale represents a tenfold change in H concentration

67 ph ph 7 neutral ph below 7 acidic ph above 7 basic/alkaline [H+] = [OH-] [H+] > [OH-] [H+] < [OH-] Buffers chemicals that can regulate ph change

68 [H + ]=[OH ] Increasingly basic 2015 Pearson Education, Inc. OH OH OH OH H + H + OH OH Basic solution H + OH OH H + H+ H + OH OH Neutral solution H + H + H + H+ H + H + OH OH Acidic solution ph Increasingly acidic Neutral Examples 1M Sodium hydroxide (ph 14) Oven cleaner, lye (ph 13.5) Household ammonia (ph ) Household bleach (ph 9.5) Egg white (ph 8) Blood (ph 7.4) Milk (ph ) Black coffee (ph 5) Wine (ph ) Lemon juice, gastric juice (ph 2) 1M Hydrochloric acid (ph 0)

69 Assignment Due Friday: Read Text pg ; take notes. Chemistry Atoms, Molecules, Bonds, Reactivity Biochemistry Water, Salts, ph Workbook pg Done Early? Read ahead: Ch 2 (all) and Workbook up to p.27

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71 Chemical Reactions Many biological molecules are polymers, such as carbohydrates and proteins Polymer: chainlike molecule made of many similar or repeating units (monomers)

72 Carbon Compounds: Biological Molecules Chemistry of Carbon - Organic chemistry is the study of all compounds that contain bonds between carbon atoms. The most versatile element!

73 Carbon Compounds Carbon can form single, double or triple bonds with other elements. Each line represents 1 covalent bond (2 electrons). methane acetylene benzen

74 Giant Molecules Macromolecules, or giant molecules are formed from monomers, small units that are joined together to form polymers, by a process called polymerization.

75 There are 4 groups of macromolecules 1.Carbohydrates 2.Lipids 3.Proteins 4.Nucleic Acids

76 Important Organic Compounds Carbohydrates Contain carbon, hydrogen, and oxygen Include sugars and starches Classified according to size Monosaccharides simple sugars Disaccharides two simple sugars joined by dehydration synthesis Polysaccharides long-branching chains of linked simple sugars 2015 Pearson Education, Inc.

77 Carbohydrates Monosaccharides simple sugars Single chain or single-ring structures Contain 3 to 7 carbon atoms Examples: glucose (blood sugar), fructose, galactose, ribose, deoxyribose

78 Carbohydrates Monosaccharides are single sugar molecules

79 Carbohydrates Disaccharides two simple sugars joined by dehydration synthesis Examples include sucrose, lactose, and maltose

80 Carbohydrates Starch polymer of glucose monomers!

81 Carbohydrates Polysaccharides are large molecules made with monosaccharides

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83 Important Organic Compounds Lipids Most abundant are Triglycerides Phospholipids Steroids Contain C, H, O C and H outnumber O Insoluble in water, but soluble in other lipids

84 Lipids Made mostly from carbon and hydrogen C, H Used to store energy form biological membranes as waterproof covering as chemical messengers

85 Lipids Common lipids in the human body Neutral fats (triglycerides) Found in fat deposits Source of stored energy Has three fatty acids and one glycerol molecule Saturated fatty acids Unsaturated fatty acids

86 Lipids triglyceride structure

87 Lipids (fats) - saturated

88 Lipids (fats) - unsaturated

89 Lipids Good and Bad Fats in Your Diet Trans fats Oils solidified by the addition of hydrogen atoms at double bond sites Increase risk of heart disease

90 Lipids Good and Bad Fats in Your Diet Omega-3 fatty acids Found in cold-water fish and plant sources, flax, pumpkin, and chia seeds; walnuts and soy foods Appears to decrease risk of heart disease

91 Lipids Common lipids in the human body (continued) Phospholipids Contain two fatty acids rather than three Phosphorus-containing head carries an electrical charge and is polar Charged region interacts with water and ions while the fatty acid chains ( tails ) do not Form cell membranes 2015 Pearson Education, Inc.

92 Phospholipids Structural component of cell membrane

93 Lipids Common lipids in the human body (continued) Steroids Formed of four interlocking rings cholesterol, bile salts, vitamin D, and some hormones Some cholesterol is ingested from animal products. The liver also makes cholesterol Cholesterol is the basis for all steroids made in the body 2015 Pearson Education, Inc.

94 Steroids Hormones: chemical messengers

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96 Nucleic Acids Nucleic acids store and transmit hereditary, or genetic, information. ribonucleic acid (RNA) deoxyribonucleic acid (DNA)

97 Nucleic Acids Nucleotides are made out of H, O, N, C and P and they contain three parts: a 5-carbon sugar a phosphate group a nitrogenous base Monomer of nucleic acid

98 Nucleic Acids Monomers of nucleotides joined together to form nucleic acid.

99 Important Organic Compounds Nucleic acids Make up genes Composed of carbon, oxygen, hydrogen, nitrogen, and phosphorus atoms Largest biological molecules in the body 2015 Pearson Education, Inc.

100 Nucleic Acids Built from nucleotides containing three parts: 1. A nitrogenous base A Adenine G Guanine C Cytosine T Thymine U Uracil 2. Pentose (five-carbon) sugar 3. A phosphate group 2015 Pearson Education, Inc.

101 Nucleic Acids Deoxyribonucleic acid (DNA) The genetic material found within the cell s nucleus Provides instructions for every protein in the body Organized by complimentary bases to form a doublestranded helix Contains the sugar deoxyribose and the bases adenine, thymine, cytosine, and guanine Replicates before cell division 2015 Pearson Education, Inc.

102 Nucleic Acids Ribonucleic acid (RNA) Carries out DNA s instructions for protein synthesis Created from a template of DNA Organized by complementary bases to form a singlestranded helix Contains the sugar ribose and the bases adenine, uracil, cytosine, and guanine Three varieties are messenger, transfer, and ribosomal RNA 2015 Pearson Education, Inc.

103 Nucleic Acids Adenosine triphosphate (ATP) Composed of a nucleotide built from ribose sugar, adenine base, and three phosphate groups Chemical energy used by all cells Energy is released by breaking high-energy phosphate bond ATP is replenished by oxidation of food fuels 2015 Pearson Education, Inc.

104 Figure 2.22 ATP structure and hydrolysis. Adenine High energy bonds P P P Phosphates Ribose (a) Adenosine triphosphate (ATP) H 2 O P P P P P P i Energy ATP Adenosine diphosphate (ADP) (b) Hydrolysis of ATP 2015 Pearson Education, Inc.

105 Nucleic Acids ATP P A B P i ADP P i ADP (adenosine diphosphate) accumulates as ATP is used for energy Three examples of how ATP drives cellular work are shown next 2015 Pearson Education, Inc. (a) Chemical work. ATP provides the energy needed to drive energy-absorbing chemical reactions. ATP ATP Membrane protein Solute P ADP (b) Transport work. ATP drives the transport of certain solutes (amino acids, for example) across cell membranes. Relaxed smooth muscle cell P i Contracted smooth muscle cell P i ADP (c) Mechanical work. ATP activates contractile proteins in muscle cells so that the cells can shorten and perform mechanical work. P i

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107 Proteins Function Build bones and muscles Control the rate of reactions enzymes Transport substances into or out of cells Help fight disease - antibodies

108 Proteins Contain N, C, H, O and S Monomers of amino acids form proteins There are 20 different amino acids that occur in nature!!

109 Proteins chains of amino acids

110 Protein Shape Up to 4 Levels of Organization 1. Sequence 2. Amino acids in the chain are twisted or folded 3. Chain is twisted or folded 4. Complex proteins with multiple chains each chain has a specific arrangement. Protein shape is very important!!!!

111 Important Organic Compounds Proteins Account for over half of the body s organic matter Provide for construction materials for body tissues Play a vital role in cell function Act as enzymes, hormones, and antibodies Contain carbon, oxygen, hydrogen, nitrogen, and sometimes sulfur Built from amino acids 2015 Pearson Education, Inc.

112 Proteins Amino acid structure Contain an amine group (NH 2 ) Contain an acid group (COOH) Vary only by R groups 2015 Pearson Education, Inc.

113 Figure 2.17 Amino acid structures. Amine group Acid group (a) Generalized structure of all amino acids. (b) Glycine is the simplest amino acid. (c) Aspartic acid (an acidic amino acid) has an acid group ( COOH) in the R group. (d) Lysine (a basic amino acid) has an amine group ( NH 2 ) in the R group. (e) Cysteine (a basic amino acid) has a sulfhydryl ( SH) group in the R group, which suggests that this amino acid is likely to participate in intramolecular bonding Pearson Education, Inc.

114 Proteins Protein structure Polypeptides contain fewer than 50 amino acids Large proteins may have 50 to thousands of amino acids Sequence of amino acids produces a variety of proteins 2015 Pearson Education, Inc.

115 Proteins Structural levels of proteins Primary structure Secondary structure Alpha helix Beta-pleated sheet Tertiary structure Quaternary structure 2015 Pearson Education, Inc.

116 Figure 2.18a The four levels of protein structure. Cys Glu Leu Ala Ala Ala Ala Met Lys Arg His Gly Leu Aps (a) Primary structure. A protein s primary structure is the unique sequence of amino acids in the polypeptide chain. Amino acids 2015 Pearson Education, Inc.

117 Figure 2.18b The four levels of protein structure. Hydrogen bonds Alphahelix β-pleated sheet (b) Secondary structure. Two types of secondary structure are the alpha-helix and beta-pleated sheet. Secondary structure is reinforced by hydrogen bonds, represented by dashed lines in the figure Pearson Education, Inc.

118 Figure 2.18c The four levels of protein structure. Polypeptide (single subunit) (c) Tertiary structure. The overall threedimensional shape of the polypeptide or protein is called tertiary structure. It is reinforced by chemical bonds between the R-groups of amino acids in different regions of the polypeptide chain Pearson Education, Inc.

119 Figure 2.18d The four levels of protein structure. Complete protein, with four polypeptide subunits (d) Quaternary structure. Some proteins consist of two or more polypeptide chains. For example, four polypeptides construct hemoglobin, the blood protein. Such proteins have quaternary structure Pearson Education, Inc.

120 Proteins Fibrous (structural) proteins Appear in body structures Exhibit secondary, tertiary, or even quaternary structure Bind structures together and exist in body tissues Stable proteins Examples include collagen and keratin 2015 Pearson Education, Inc.

121 Figure 2.19a General structure of (a) a fibrous protein and (b) a globular protein. (a) Triple helix of collagen (a fibrous or structural protein) Pearson Education, Inc.

122 Proteins Globular (functional) proteins Function as antibodies, hormones, or enzymes Exhibit at least tertiary structure Can be denatured and no longer perform physiological roles Active sites fit and interact chemically with other molecules 2015 Pearson Education, Inc.

123 Figure 2.19b General structure of (a) a fibrous protein and (b) a globular protein. Heme group Globin protein (b) Hemoglobin molecule composed of the protein globin and attached heme groups. (Globin is a globular or functional protein.) 2015 Pearson Education, Inc.

124 Enzymes Act as biological catalysts Increase the rate of chemical reactions Bind to substrates at an active site to catalyze reactions Recognize enzymes by their ase suffix Hydrolase Oxidase 2015 Pearson Education, Inc.

125 Figure 2.20 A simplified view of enzyme action. Substrates (S) e.g., amino acids Energy is absorbed; bond is formed. Water is released. H 2 O Product (P) e.g., dipeptide Peptide bond Active site Enzyme-substrate complex (E-S) Enzyme (E) 1 Substrates bind at active site, temporarily forming an enzyme-substrate complex. 2 The E-S complex undergoes internal rearrangements that form the product. Enzyme (E) 3 The enzyme releases the product of the reaction Pearson Education, Inc.

126 Assignment Due Wed: Read Text p ; take notes. Organic Compounds Carbs, Lipids, Nucleic Acids, Proteins, ATP Workbook p Complete Biological Molecules packet, with partner(s) Done Early? Read ahead: Ch 3

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