Chapter 2 Chemistry KS Lecture.pdf
Transcript
Matter Anything that has mass and occupies space Chemistry Is the study of matter and its interactions © 2019 Pearson Education, Inc. Figure 2.1 Structure of a representative atom. Atom-smallest unit of matter that sti...
Matter Anything that has mass and occupies space Chemistry Is the study of matter and its interactions © 2019 Pearson Education, Inc. Figure 2.1 Structure of a representative atom. Atom-smallest unit of matter that still retains its original properties © 2019 Pearson Education, Inc. Figure 2.1 Structure of a representative atom. 1st shell-closest to nucleus –holds 2 electrons 2nd shell –holds 8 electrons 3rd can hold 18-satisfied with 8 electrons © 2019 Pearson Education, Inc. Figure 2.2 Elements in the human body and their positions in the periodic table. Element- substance that cannot be broken down to a simpler substance by chemical means © 2019 Pearson Education, Inc. 1.Elements are defined by atomic number=number of protons 2.Periodic table is listed by chemical symbol usually first letter or two of elements name H = Hydrogen © 2019 Pearson Education, Inc. Elements of human body 3% 4% 10% 18% Oxygen 65% Carbon Hydrogen Nitrogen Mineral © 2019 Pearson Education, Inc. Unnumbered Figure 2.1_page 34 Isotopes-Atoms with the same atomic numbers but different mass numbers Certain isotopes have very high energy which makes them unstable. These isotopes release energy in the form of radiation and form basis of nuclear medicine Common applications are 1) Cancer radiation therapy 2) Radiotracers 3) Treatment of thyroid disorders © 2019 Pearson Education, Inc. Structure of Hydrogen and Its 3 Isotopes Hydrogen-One Hydrogen-Two Hydrogen-Three All of these have the same number of protons and are thus the same element. They differ by the number of protons and by their mass. ISO = Same = same element 8 Figure 2.3 The three types of mixtures. Mixture-atoms of two or more elements are physically intermixed © 2019 Pearson Education, Inc. Figure 2.3a The three types of mixtures. © 2019 Pearson Education, Inc. Figure 2.3b The three types of mixtures. © 2019 Pearson Education, Inc. Figure 2.3c The three types of mixtures. © 2019 Pearson Education, Inc. Solute-substance that dissolves Solvent-the substance in which the solute dissolves Water is the most important solvent in the human body Concentration- The amount of solute present in a solution ie: If a solution has 10 grams of salt and 90 millilliters of water we call it 10/100 or 10% salt solution Remember that a solution is a mixture because neither the solvent nor the solution changes chemically If you want to separate the salt from the water you could do so by physical means © 2019 Pearson Education, Inc. Molecule-two of more atoms are chemically bonded. Compound-Two of more atoms that bind are different elements example H2O © 2019 Pearson Education, Inc. Unnumbered Figure 2.2_page 36 Elemental sodium (Na) is a soft metal Valence electrons determine how an atom interacts with and forms bonds with other atoms © 2019 Pearson Education, Inc. Unnumbered Figure 2.3_page 36 Chlorine (CL) is a poisonous gas © 2019 Pearson Education, Inc. Figure 2.4-0 Formation of an ionic bond. © 2019 Pearson Education, Inc. Electrons are transferred Formation of an ionic bond between a metal atom and a nonmetal atom © 2019 Pearson Education, Inc. Ion-a charged particle the sodium has 11 protons. The sodium atom gives up its lone outer electron Now has only 10- electrons A charged particle has a +1 charge is specifically called a cation Cl accepts an electron and is becomes a -1 charge is called anion © 2019 Pearson Education, Inc. Figure 2.5 Formation of a covalent bond. Covalent bond- involves sharing electrons between two or more nonmetals Strongest type of chemical bond © 2019 Pearson Education, Inc. Table 2.1 Electron Sharing in Covalent Bonds At atom will share electrons until its valence shell obeys the octet or duet rule © 2019 Pearson Education, Inc. Unnumbered Figure 2.4_page 39 Nonpolar Covalent bonds- two nonmetals in a molecule have identical or nearly identical electronegativities They tug on electrons with the same force © 2019 Pearson Education, Inc. The atoms sharing the electrons are of the same element. The arrangement of the atoms makes one atom unable to pull more strongly than another atom. The bond is between carbon and hydrogen. © 2019 Pearson Education, Inc. Polar Covalent Bonds-nonmetals of different electronegativities interact The electrons spend more time around the more electronegative atom Polar-two opposite sides Polar molecules have same number or protons and electrons-are electrically neutral © 2019 Pearson Education, Inc. Figure 2.6 Nonpolar vs. polar covalent bonds. © 2019 Pearson Education, Inc. Figure 2.7a Hydrogen bonding and surface tension between water molecules. Hydrogen bond- weak attraction between the partially positive hydrogen atoms and partially negative nonmetal atoms in polar molecules Hydrogen bonds differ from ionic and covalent 1) No true bonds. Electrons are neither shared or transferred 2) Generally found between molecules © 2019 Pearson Education, Inc. Figure 2.7b Hydrogen bonding and surface tension between water molecules. Where air and water meet, the polar water molecules are more strongly attracted to one another than they are to the nonpolar air molecules. © 2019 Pearson Education, Inc. Unnumbered Figure 2.5_page 40 © 2019 Pearson Education, Inc. Unnumbered Figure 2.6_page 40 © 2019 Pearson Education, Inc. Unnumbered Figure 2.7_page 41 © 2019 Pearson Education, Inc. Table 2.2 Chemical Bonds © 2019 Pearson Education, Inc. Chemical reaction-Any time chemical bonds are formed, broken or rearranged or when electrons are transferred between two or more atoms(or molecules). Chemical notation- series of symbols or abbreviations used to demonstrate what occurs in a reaction Letter or letters represent the element Subscript numbers tell you how many atoms of each element make up a molecule Chemical Equation Reactants- The substances you are starting with that will undergo a reaction on left side of the equation Products-the substance produced in the reaction The arrow signifies that the reactants on the left have interacted to for the products Two arrows pointing in opposite directions indicates that the reaction is reversible © 2019 Pearson Education, Inc. Energy The capacity to do work Potential Energy stored, ready to be released and used to do work Kinetic Energy in motion © 2019 Pearson Education, Inc. Unnumbered Figure 2.8_page 42 © 2019 Pearson Education, Inc. Energy in the human body Chemical energy-inherit in chemical bonds. It is the from of energy that drives nearly all cellular processes Electrical Energy-generated by movement of charged particles. This energy allows nerve cells to communicate Mechanical energy-Energy transferred from one object to another. This is the process by which skeletal muscle generates a contraction © 2019 Pearson Education, Inc. Energy must be invested any time a chemical reaction occurs Endergonic Require energy from another source to proceed Products contain more energy than the reactants Exergonic Excess energy stored in reactants is released leaving products with less energy than the reactants. © 2019 Pearson Education, Inc. Catabolic larger substances are broken down to smaller ones: generally exergonic Exchange One or more atoms from the reactants are exchanged for another Anabolic Reactions that create new chemical bonds © 2019 Pearson Education, Inc. Types of Chemical Reactions Figure 2.12 d) In a reversible reaction, bonds are broken, reformed and the rebuilt. Bookworm → Book + Worm Figure 2.8-2 Activation energy. For a reaction to occur, atoms must collide with enough force to overcome the repulsion of their electrons. The faster these collisions occur, the faster the reactions proceeds. All chemical reactions require the input of some energy to overcome the repulsion of the atoms’ electrons and to allow strong collisions to take place. This energy is called activation energy © 2019 Pearson Education, Inc. Factors that affect the rate of reactions Concentration Temperature Properties of the reactants(both the size of the particles and phase (gas, liquid, or solid) Presence or absence of a catalyst ( a catalyst is a substance that increases reaction rate by lowering the activation energy). © 2019 Pearson Education, Inc. Figure 2.9 The effect of enzymes on activation energy. © 2019 Pearson Education, Inc. Enzymes Enzymes speed up reactions Enzymes are highly specific for individual substrates and reactions Enzymes do not alter the chemical reaction Enzymes are not permanently altered in the reaction © 2019 Pearson Education, Inc. Figure 2.10 Enzyme-substrate interaction. © 2019 Pearson Education, Inc. Figure 2.10-1-2 Enzyme- substrate interaction. © 2019 Pearson Education, Inc. Figure 2.10-3-4 Enzyme- substrate interaction. © 2019 Pearson Education, Inc. Properties of Water Water absorbs heat without changing significantly in temperature itself. Water carries heat with it when it changes from a liquid to a gas. Water cushions and protects the body’s structures. Water acts as a lubricant between two adjacent surfaces © 2019 Pearson Education, Inc. Water is the universal solvent because so many solutes will dissolve in it fully or at least partially. Water’s ability to dissolve substances has to do with 1)its molecular shape 2) polar covalent bonds These two factors combine to “grab” certain solutes and pull them apart Water is only able to dissolve solutes known as hydrophilic(water loving) Hydrophilic solutes have fully or partially charged ends Hydrophobic include uncharged polar covalent molecules or compounds such as methane, oils, and fats © 2019 Pearson Education, Inc. Figure 2.11a The behavior of hydrophilic and hydrophobic molecules in water. © 2019 Pearson Education, Inc. Figure 2.11b The behavior of hydrophilic and hydrophobic molecules in water. © 2019 Pearson Education, Inc. Figure 2.11c The behavior of hydrophilic and hydrophobic molecules in water. © 2019 Pearson Education, Inc. Figure 2.12a The behavior of acids and bases in water. © 2019 Pearson Education, Inc. Figure 2.12b The behavior of acids and bases in water. An acid is a hydrogen ion donor The number of hydrogen ions in the solution increase © 2019 Pearson Education, Inc. Figure 2.12c The behavior of acids and bases in water. A base is a hydrogen ion acceptor. Also called alkali The number of hydrogen ion in the solution decreases. © 2019 Pearson Education, Inc. Acids, Bases, and pH H2O → H+ + OH- Acidic: pH lower than 7.0 High H+ concentration Low OH— concentration Basic (or alkaline): pH higher than 7.0 Low H+ concentration High OH— concentration Figure 2.12 The behavior of acids and bases in water. pH scale represents the hydrogen ion concentration in a solution A solution with a ph less than 7 is acidic A solution with a ph greater than 7 is basic Each single-digit change corresponds to a 10- fold change in hydrogen ion concentration © 2019 Pearson Education, Inc. Buffers- chemical systems that resist changes in pH to prevent any large swings. A buffer consists of a weak acid and its corresponding anion. One of the main buffers in the body is the carbonic acid- bicarbonate buffer system (i.e. the blood becomes too basic) carbonic acid releases hydrogen ions into the blood to off set the increase in pH (i.e. the blood becomes too acidic) bicarbonate ions bond to hydrogen ions in the blood taking them out of the solution and offset the decrease in pH. The two main organ systems in the body that work to correct pH imbalances are the respiratory and urinary systems. © 2019 Pearson Education, Inc. Reversible Reactions: Carbonic Acid-Bicarbonate Equilibrium H2CO3 → H+ + HCO3- H2CO3 is Carbonic acid(weak acid) HCO3- is Bicarbonate(anion) Salt and Electrolytes Salt- any metal cation and nonmetal anion held together by ionic bond. The resulting cations and anions in the solution are called electrolytes Electrolytes will conduct an electric current in water All salts dissociate into electrolytes do some acids and bases Salts in the body Calcium in bones and teeth as well as heart and muscle Sodium and potassium in muscle and nerve cell © 2019 Pearson Education, Inc. Organic Compounds-Carbohydrates, lipids, Proteins, and Nucleotides Organic-chemicals produced by living organisms. They are generally larger and more complex than inorganic compounds The carbon-hydrogen backbone forms the basis for all organic compounds © 2019 Pearson Education, Inc. Unnumbered Figure 2.9_page 51 © 2019 Pearson Education, Inc. Monomers –single subunits that can be combined to build larger structures Polymers- large structures that consist of many monomers linked together They are built by an anabolic reaction called dehydration synthesis Dehydration synthesis you have two monomers linked by a covalent bond. The products are a polymer compound and a molecule of water. Hydrolysis- (water splitting) This is the opposite of dehydration synthesis. This is where a molecule of water is added to a polymer, water is split apart and covalent bonds of the monomers are broken. © 2019 Pearson Education, Inc. Carbohydrate monomers are composed of Figure 2.14 carbon hydrogen and oxygen in a ratio of 1:2:1 Carbohydrates: They contain –OH groups and are polar and hydrophilic structure of They are scattered throughout membranes that monosaccharides. surround cell and genetic material © 2019 Pearson Education, Inc. Figure 2.14a Carbohydrates: structure of monosaccharides. © 2019 Pearson Education, Inc. Figure 2.14b Carbohydrates: structure of monosaccharides. Isomer-Compound with same molecular formula but different structure Glucose is the body’s primary source of fuel Fructose-found in fruits and vegetables Galactose-found in dairy products © 2019 Pearson Education, Inc. Monosaccharides have from three to seven Figure 2.15 carbon atoms. In the human body most are five Carbohydrates: formation or six carbons and breakdown of disaccharides. Disaccharide- compound with two monosaccharides joined by a polar covalent bond. © 2019 Pearson Education, Inc. Figure 2.16 Carbohydrates: the polysaccharide glycogen. Polysaccharide-long branching chains of Low solubility due to their Storage of glucose in plants in animals-glycogen(stored monosaccharides joined by size –starch in liver and skeletal muscle) covalent bonds formed by dehydration synthesis © 2019 Pearson Education, Inc. Table 2.3-1 Organic Compounds © 2019 Pearson Education, Inc. Figure 2.17 Lipids: structure of fatty acids. Lipids include fats and oil Like carbohydrates, lipids contain carbon, hydrogen and oxygen, the difference is carbon and hydrogen are its main components and oxygen is a minority component. Functional group –COOH Carboxylic acid group The predominance of carbon and hydrogen makes it very nonpolar and hydrophobic © 2019 Pearson Education, Inc. Figure 2.17a Lipids: Saturated fatty acid- no double bonds between carbon and hydrocarbon chain structure of fatty They are found primarily in animal fats and acids. mostly solid at room temperature © 2019 Pearson Education, Inc. Figure 2.17b Lipids: Monounsaturated-has one double bond structure of fatty Hydrocarbons can’t pack together as closely. They are generally liquid at room temperature acids. © 2019 Pearson Education, Inc. Figure 2.17c Lipids: structure of fatty acids. Polyunsaturated- two or more double bonds between carbon atoms. Lowest melting point of all other fatty acids and liquid at room temperature. © 2019 Pearson Education, Inc. Figure 2.18 Lipids: structure and formation of triglycerides. Fatty acids are stored by linking three of them via dehydration synthesis to a modified three carbon sugar called glycerol. These reactions produce a polymer called a neutral fat, or triglyceride © 2019 Pearson Education, Inc. Figure 2.19a Lipids: structure of phospholipids. Phospholipid- main component of the cell membrane. This is a class of lipids whose molecule has a hydrophilic head containing a phosphate group and two fatty acid tails which are very nonpolar and hydrophobic © 2019 Pearson Education, Inc. Figure 2.19c Lipids: structure of phospholipid s. Compounds with strongly polar and strongly nonpolar parts are known as amphiphilic © 2019 Pearson Education, Inc. Figure 2.20a Lipids: structure of steroids. Steroids are a class of lipids that share a four-ring hydrocarbon structure called a steroid nucleus.. © 2019 Pearson Education, Inc. Figure 2.20b Lipids: structure of steroids. The steroid cholesterol forms the basis for the body’s other steroids including bile acids that aid in digestion and sex hormones estrogen and testosterone © 2019 Pearson Education, Inc. Protein Proteins make up hair, nails, and skin Proteins give bones their structure Proteins act as enzymes, play vital structural roles, function in the body’s defenses, allow cells to communicate Proteins make muscles to contract Proteins can be oxidized as fuel © 2019 Pearson Education, Inc. The monomer of all proteins is an amino acid All amino acids have the same core structure carbon, hydrogen, oxygen and nitrogen Figure 2.21a Proteins: structure of amino acids. © 2019 Pearson Education, Inc. Figure 2.21b Proteins: structure of amino acids. R(residue) group determines the behavior and properties of the amino acid © 2019 Pearson Education, Inc. Figure 2.22 Proteins: formation and breakdown of dipeptides. Peptide is the joining of two amino acids joined by a polar covalent bond(peptide bond) Peptides are named for the number of amino acids they contain i.e. dipeptides consist of two amino acids © 2019 Pearson Education, Inc. Protein Structure 1)Fibrous proteins-long protein strands mostly nonpolar amino acids Found in hair, nails, tendons and bones Think : they not only resemble ropes and act to tie or connect body structures 2)Globular proteins –are spherical or globe shaped These function as enzymes, hormones and cell messengers Both structures are highly complex these structures are divided into four levels © 2019 Pearson Education, Inc. Figure 2.23a Levels of protein structure. Includes amino acids held together by covalent peptide bonds © 2019 Pearson Education, Inc. Figure 2.23b Organizing a polypeptide into a functional Levels of protein protein id folding one of more segments over in a characteristic way structure. © 2019 Pearson Education, Inc. Figure 2.23c Levels of protein structure. To become functional the polypeptide must fold into a tertiary structure (a three- dimensional shape) © 2019 Pearson Education, Inc. A protein that loses its shape cannot function Figure 2.23d properly. The process that destroys a proteins shape is called denaturation Levels of protein Many things can denature a protein including structure. heat, ph changes, and chemicals such as alcohol. © 2019 Pearson Education, Inc. Figure 2.24 Structure of nucleotide s. © 2019 Pearson Education, Inc. Figure 2.24a Structure of nucleotides. Nucleotides-monomers that form our genetic material These organic compounds are not oxidized by the cell for fuel, however nucleotides do play a key role in energy systems of the body ATP is our main source of chemical energy that drives nearly all cellular processes. © 2019 Pearson Education, Inc. Figure 2.24b Structure of nucleotides. Purines are double ringed compounds Pyrimidines are single ring compounds © 2019 Pearson Education, Inc. Figure 2.25 Nucleotides: structure and formation of ATP ATP is generally synthesized by adding a third phosphate to ADP The cell makes ATP through the catabolism of organic compounds primarily glucose © 2019 Pearson Education, Inc. Figure 2.25b Nucleotides: structure and formation of ATP A molecule of ATP last 60 seconds in the cell before it is hydrolyzed, as nearly every process in the cell is driven by the energy released by ATP hydrolysis. Oxygen is required for most ATP synthesis. © 2019 Pearson Education, Inc. Unnumbered Figure 2.10_page 60 The sugar linked to the phosphate group form the nucleic acids backbone. The nitrogenous base extend out to the side and do not participate in the linkage of the nucleotide strand © 2019 Pearson Education, Inc. Figure 2.26-2 Structure of the nucleic acids DNA and RNA. The two main nucleic acids are 1)DNA-deoxyribonucleic acid 2) RNA-ribonucleic acid Together they are responsible for storage and execution of the genetic code © 2019 Pearson Education, Inc. Base Pairing: G bonds to C (C bonds to G) A bonds to T (or U) (T bonds to A) DNA-is composed of two long strands of nucleotides that twist around each other to form a double helix DNA is in the nucleus Fig. 2.26 © 2019 Pearson Education, Inc. Figure 2.26b Structure of the nucleic acids DNA and RNA. Single strand RNA The task of assembling the correct amino acid sequence for a protein falls to RNA RNA is a single strand of nucleotides and is not confined to the nucleus of a cell © 2019 Pearson Education, Inc. Which sub-atomic particle is positively charged? A A. Atoms B B. Neutrons C C. Carbon D D. Protons E E. Electrons © 2019 Pearson Education, Inc. Cholesterol belongs to which major group of organic compounds? A A. Nucleic Acids B B. Lipids C C. Carbohydrates D D. Proteins E E. No clue © 2019 Pearson Education, Inc. Enzymes are made out of ____? which are one of the major groups of organic compounds. A A. Nucleic Acids B B. Lipids C C. Carbohydrates D D. Proteins E E. No clue Starch belongs to which major group of organic compounds? A A. Nucleic Acids B B. Lipids C C. Carbohydrates D D. Proteins E E. No clue Enzymes speed up chemical reactions by? A. Changing the pH B. Providing energy to drive the reaction C. Lowering the activation energy D. Acting as buffers E. No clue What type of reaction creates a glucose and a fructose from sucrose molecule? A. Hydrogenation B. Hydrolysis C. Dehydration Synthesis D. Dehydrolysis E. Dehydrogenation A mixture of Carbonic Acid and Bicarbonate in your blood stream helps to keep your pH stable. This mixture is called ??? A. an equilibrium B. a buffer C. a chemical reaction D. a dynamic duo E. No clue A pH of 5 would be considered to be? A A. Acidic B B. Basic C C. Neutral D D. Not sure E E. No clue Cl is the symbol for which element? A A. Carbon B B. Carbon-Iodine C C. Calcium D D. Chlorine E E. No clue
