Atoms The study of chemistry begins with the basic unit of matter, the atom.

The subatomic particles that make up atoms are protons neutrons electrons

C stands for carbon. Na stands for sodium. Elements A pure substance that consists entirely of one type of atom. C stands for carbon. Na stands for sodium.

Atomic Number The number of protons in an atom Every Element has a Different Atomic # CHNOPS

Atoms of the same element that differ in the number of neutrons. Isotopes Atoms of the same element that differ in the number of neutrons.

Because they have the same number of electrons, these isotopes of carbon have the same chemical properties. The difference among the isotopes is the number of neutrons in their nuclei.

Radioactive Isotopes Their nuclei are unstable and lose particles at a constant rate over time

Radioactive isotopes can be used: to determine the ages of rocks and fossils. to treat cancer. to kill bacteria that cause food to spoil. as labels or “tracers” to follow the movement of substances within an organism.

Chemical Compounds A substance formed by the chemical combination of two or more elements in definite proportions.

Water H2O Table Salt NaCl Hydrochloric Acid HCl Glucose C6H12O6 Chemical Formula Water H2O Table Salt NaCl Hydrochloric Acid HCl Glucose C6H12O6

The electrons that form bonds are called valence electrons. Chemical Bonds Hold atoms in compounds together The electrons that form bonds are called valence electrons.

The main types of chemical bonds are: ionic bonds covalent bonds

Ionic Bonds Formed when one or more electrons are transferred from one atom to another. These positively and negatively charged atoms are known as ions.

Sodium atom (Na) Chlorine ion (Cl-) Sodium ion (Na+) Chlorine atom (Cl) The chemical bond in which electrons are transferred from one atom to another is called an ionic bond. The compound sodium chloride forms when sodium loses its valence electron to chlorine. Protons +11 Electrons - 11 Charge 0 Protons +11 Electrons - 10 Charge +1 Protons +17 Electrons - 17 Charge 0 Protons +17 Electrons - 18 Charge -1

Covalent Bonds Electrons are shared by atoms instead of being transferred.

single covalent bond double bond triple bond

The structure that results when atoms are joined together by covalent bonds is called a molecule.

Van der Waals Forces When molecules are close together, a slight attraction can develop between the oppositely charged regions of nearby molecules. d- d+ d- d+

Quiz 4-1

The particles that move around the nucleus of an atom are called electrons. protons. neutrons. isotopes. 21

The atomic number of a carbon atom is 6 The atomic number of a carbon atom is 6. How many neutrons does the isotope carbon-14 have? 14 12 8 6

Which of the following statements about the three isotopes of carbon is true? They are all radioactive. They have different numbers of electrons. They have the same number of protons and neutrons. They have the same chemical properties but differ in atomic mass.

A chemical compound consists of Electrons mixed with neutrons. at least three elements combined by ionic or covalent bonds. two or more protons combined in any proportion. two or more elements combined in a definite proportion.

Van der Waals forces are the result of ionic bonds. unequal sharing of electrons. the bonding of different isotopes. the chemical combination of sodium and chlorine.

Copyright Pearson Prentice Hall Organic Chemistry The study of all compounds that contain bonds between carbon atoms. Copyright Pearson Prentice Hall 26

Polymers Macromolecules Macromolecules Video Macromolecules are formed by a process known as polymerization. Monomers Polymers Macromolecules Video 27

Four groups of organic compounds found in living things are: carbohydrates lipids nucleic acids proteins Macromolecules! 28

What is the function of carbohydrates? Source of Energy Structure 29

Carbohydrates Compounds made up of carbon, hydrogen, and oxygen atoms, usually in a ratio of 1 : 2 : 1. 30

Different sizes of carbohydrates: Monosaccharides Glucose Disaccharides Sucrose Polysaccharides Starch 31

Starches and sugars are examples of carbohydrates that are used by living things as a source of energy. Starch Examples: Cellulose Starch Glycogen Structure Starches and sugars are examples of carbohydrates that are used by living things as a source of energy. Starches form when sugars join together in a long chain. Glucose 32

Lipids Generally not soluble in water. Fats Oils Waxes Steroids 33

Cellular lipids are in cell membranes and waterproof coverings Used to store energy Cellular lipids are in cell membranes and waterproof coverings Phospholipids Fatty Acids Triglycerides (Glycerol & 3 FAs) 34

Fluid Mosaic Model 35

Saturated Fat Unsaturated Fat Triglyceride 36

Nucleic Acids Polymers assembled from individual monomers known as nucleotides. 37

Nucleotides consist of three parts: a 5-carbon sugar a phosphate group a nitrogenous base 38

Nucleotides Purines Adenine Guanine Pyrimidines Thymine Cytosine 39

Nucleic acids store and transmit hereditary, or genetic, information. ribonucleic acid (RNA) deoxyribonucleic acid (DNA) 40

Cytosine bonds to Guanine (3 H bonds) Chargaff’s Rules Cytosine bonds to Guanine (3 H bonds) Thymine bonds to Adenine (2 H bonds) Chargaff’s Rules %C = %G %T = %A Complementary Base Paring 41

Adenosine Triphosphate ATP Adenosine Triphosphate 42

Monomers of proteins are called amino acids. Contain nitrogen, carbon, hydrogen, and oxygen. Monomers of proteins are called amino acids. 43

The portion of each amino acid that is different is a side chain called an R-group. 44

The instructions for arranging amino acids into many different proteins are stored in DNA. Protein Molecule Amino Acids Proteins help to carry out chemical reactions, transport small molecules in and out of cells, and fight diseases. Proteins are made up of chains of amino acids folded into complex structures. 45

Introduction to “Fold – It” Some functions of proteins: Control rate of reactions – Enzymes Used to form bones and muscles Transport substances into or out of cells Help to fight disease - antibodies Introduction to “Fold – It” 46

Enzymes are Biological Catalysts. Some chemical reactions are too slow to be of value. These chemical reactions are made possible by catalysts. Enzymes are Biological Catalysts. 47

Enzymes speed up chemical reactions that take place in cells. 48

The Enzyme-Substrate Complex 49

An Enzyme-Catalyzed Reaction The enzyme hexokinase converts the substrates glucose and ATP into glucose-6-phosphate and ADP. 50

Changes in temperature Enzyme or substrate concentrations Regulation of Enzyme Activity pH values Changes in temperature Enzyme or substrate concentrations 51

Quiz 4-2 52

Large carbohydrate molecules such as starch are known as polysaccharides. monosaccharides. proteins. lipids. 53

Many lipids are formed from glycerol and fatty acids. monosaccharides. amino acids. nucleic acids. 54

Proteins are among the most diverse macromolecules because they contain both amino groups and carboxyl groups. their R groups can be either acidic or basic. they contain nitrogen as well as carbon, hydrogen, and oxygen. they can twist and fold into many different and complex structures. 55

Which of the following statements about cellulose is true? Animals make it and use it to store energy. Plants make it and use it to store energy. Animals make it and use it as part of the skeleton. Plants make it and use it to give structural support to cells. 56

A major difference between polysaccharides and proteins is that plants make polysaccharides, while animals make proteins. polysaccharides are made of monosaccharides, while proteins are made of amino acids. proteins are made of monomers, while polysaccharides are not. proteins carry genetic information, while polysaccharides do not. 57

Water Evaporation Sublimation Condensation Transpiration Liquid  Gas Solid  Gas Condensation Gas Liquid Transpiration Plants give off liquid water which evaporates into the atmosphere. 58

Water Precipitation Particles accumulating from a suspension Solid or Liquid from Gas Solid from Liquid 59

A water molecule is polar because there is an uneven distribution of electrons between the oxygen and hydrogen atoms. d+ d- 60

Partial positive and negative charges attract each other. Hydrogen Bonds Partial positive and negative charges attract each other. 61

Cohesion attraction between molecules of the same substance. Because of hydrogen bonding, water is extremely cohesive. 62

Adhesion attraction between molecules of different substances. 63

Melting Point Boiling Point Capillary Action 64

Mixture a material composed of two or more elements or compounds that are physically mixed but not chemically combined. 65

Two types of mixtures can be made with water solutions suspensions 66

Solutions The components of a solution are evenly distributed throughout the solution. solute—the substance that is dissolved. solvent—the substance that does the dissolving. 67

Suspensions  Separate into layers Do not settle out easily. 68

The pH Scale Indicates the concentration of H+ ions in solution. The pH scale ranges from 0 to 14. 69

At a pH of 7, the concentration of H+ ions and OH- ions is equal. The pH Scale At a pH of 7, the concentration of H+ ions and OH- ions is equal. The concentration of H+ ions determines whether solutions are acidic or basic. 70

Acids Any compound that forms H+ ions in solution.  71

Bases A compound that produces hydroxide ions (OH- ions) in solution. 72

Buffers  The pH of the fluids within most cells in the human body must generally be kept between 6.5 and 7.5. Controlling pH is important for maintaining homeostasis. 73

Quiz 4-3 74

A molecule in which the charges are unevenly distributed is called a covalent molecule. cohesive molecule. hydrogen molecule. polar molecule. 75

A dissolved substance is called a solute. solution. solvent. suspension. 76

A compound that produces hydroxide ions in solution is called a(an) salt. buffer. acid. base. 77

Hydrogen bonds between water molecules result from adhesion between water molecules. magnetic attractions between water molecules. uneven electron distribution in each water molecule. ionic bonds in the water molecule. 78

On a pH scale, a value of 2 means that the solution has equal concentrations of H+ and OH- ions. the same concentration of H+ ions as pure water. lower concentration of H+ than in pure water. higher concentration of H+ than in pure water. 79