Chapter 2Chapter 2CHEMISTRY OF LIFECHEMISTRY OF LIFE

NATURE OF MATTERNATURE OF MATTER MatterMatter - anything - anything

that has mass and that has mass and occupies space -occupies space -consists of atomsconsists of atoms

AtomAtom – smallest unit – smallest unit of matter that cannot of matter that cannot be broken down by be broken down by chemical meanschemical means

Atom consists of Atom consists of three particles: three particles: electron(-), electron(-), proton(+), and proton(+), and neutron(0).neutron(0).

Electrons are Electrons are negatively charged negatively charged and have little mass.and have little mass.

Protons are positively Protons are positively charged and have a charged and have a mass of one.mass of one.

Neutrons have no Neutrons have no charge, but have a charge, but have a mass of one. mass of one.

Electrons and protons Electrons and protons are opposite charges, are opposite charges, so they attract each so they attract each other.other.

Figure 2.10 Electron configurations of the first 18 elements

Electron Configurations of the First 18 Elements

Active Periodic TableActive Periodic Table

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Atoms typically have Atoms typically have one electron for one one electron for one proton, so they have proton, so they have no electrical no electrical charge.charge.

ATOMIC MASSATOMIC MASS – is – is the sum of protons the sum of protons & neutrons& neutrons

ELEMENTSELEMENTS - a pure - a pure substance made of substance made of only one kind of only one kind of atomatom

Elements differ in Elements differ in the number of the number of protons referred to protons referred to as the as the ATOMIC ATOMIC NUMBERNUMBER..

The number of The number of neutrons in an atom neutrons in an atom is often but not is often but not always equal to the always equal to the number of protons in number of protons in the atom.the atom.

Atoms of an element Atoms of an element that contain different that contain different numbers of neutrons, numbers of neutrons, but same # of but same # of protons are calledprotons are called ISOTOPES.ISOTOPES.

Isotopes are written Isotopes are written with the symbol and with the symbol and mass.mass.

C-12, C-13, C-14C-12, C-13, C-14

RADIOACTIVE RADIOACTIVE ISOTOPESISOTOPES Atoms that emit Atoms that emit

radiation are said to be radiation are said to be radioactive. Many radioactive. Many elements have at least elements have at least one radioactive one radioactive isotope.isotope.

Radioactive isotopes Radioactive isotopes are frequently used as are frequently used as tracers.tracers.

Tracers are extremely Tracers are extremely valuable in diagnosing valuable in diagnosing diseases.diseases.

Radioactive isotopes Radioactive isotopes are used to treat are used to treat certain diseases. (Co-certain diseases. (Co-60 & C-14)60 & C-14)

Radioactive isotopes Radioactive isotopes can be used to kill can be used to kill bacteria that cause bacteria that cause food to spoil.food to spoil.

Radiation can Radiation can damage or kill damage or kill living things and living things and must be handled must be handled properly.properly.

Detecting Damaged Heart Detecting Damaged Heart MuscleMuscle

An isotope called An isotope called thallium-201 is used to thallium-201 is used to detect damaged heart detect damaged heart muscle after a heart muscle after a heart attack. attack.

Will accumulate only Will accumulate only in normal, undamaged in normal, undamaged heart muscleheart muscle

Cost, risk to patient Cost, risk to patient advantages & advantages & disadvantagesdisadvantages

CHEMICAL BONDINGCHEMICAL BONDING A force that joins A force that joins

atoms is called a atoms is called a chemical bond.chemical bond.

Compound – a Compound – a substance made of substance made of the joined atoms of the joined atoms of two or more two or more different elements.different elements.

Every compound is Every compound is represented by a represented by a chemical formula chemical formula that identifies the that identifies the elements in the elements in the compound and their compound and their properties.properties.

COVALENT BONDSCOVALENT BONDS Covalent bonds form Covalent bonds form

when two or more when two or more atoms share atoms share electrons to form a electrons to form a molecule.molecule.

A A molecule molecule is a is a group of atoms held group of atoms held together by covalent together by covalent bonds.bonds.

The arrangement of The arrangement of their electrons their electrons determines how determines how atoms bond togetheratoms bond together

Electrons are grouped Electrons are grouped into different levels. into different levels.

Electrons levels can hold Electrons levels can hold a limited number of a limited number of electrons.electrons.

Hydrogen (H) and Helium Hydrogen (H) and Helium (He) outer level can hold (He) outer level can hold up to 2.up to 2.

22ndnd level can hold 8 level can hold 8 electronselectrons

Higher levels can hold Higher levels can hold even greater numbers of even greater numbers of electronselectrons

Atoms want to achieve a Atoms want to achieve a stable level which is 8 stable level which is 8 electrons in the outer electrons in the outer level except H & Helevel except H & He

If the outer If the outer electron level is electron level is not full, an not full, an atom will react atom will react readily with readily with atoms that can atoms that can provide provide electrons to fill electrons to fill its outer level.its outer level.

HYDROGEN BONDSHYDROGEN BONDS The electrons in a water The electrons in a water

molecule are shared by molecule are shared by oxygen (O) and hydrogen oxygen (O) and hydrogen (H). The shared (H). The shared electrons are attracted electrons are attracted more strongly by the more strongly by the oxygen nucleus than by oxygen nucleus than by the hydrogen nuclei. the hydrogen nuclei. Molecules with an Molecules with an unequal distribution of unequal distribution of electrical charge are electrical charge are called called POLAR POLAR MOLECULES.MOLECULES. This This attraction between 2 attraction between 2 water molecules is an water molecules is an example of hydrogen example of hydrogen bond – weak chemical bond – weak chemical attraction between polar attraction between polar molecules.molecules.

Hydrogen BondsHydrogen Bonds Oxygen is one of the most Oxygen is one of the most

electronegative elementselectronegative elements In a water molecule In a water molecule

electronegative oxygen electronegative oxygen “hogs” electrons. “hogs” electrons.

This “hogging” of electrons This “hogging” of electrons results in which type of bond results in which type of bond between oxygen and between oxygen and hydrogen within the water hydrogen within the water molecule?molecule?

Polar covalent

Hydrogen bonds Hydrogen bonds

occur between occur between two polar two polar molecules, or molecules, or between different between different polar regions of polar regions of one large macro-one large macro-molecule.molecule.

One “relatively” One “relatively” negative region negative region is attracted to a is attracted to a second second “relatively” “relatively” positive region. positive region.

Figure 3.1 Hydrogen bonds between water molecules

IONIC BONDSIONIC BONDS An atom or molecule An atom or molecule

that has gained or lost that has gained or lost one or more electrons one or more electrons is called an is called an IONION. .

Ions have an electrical Ions have an electrical charge because they charge because they contain an unequal contain an unequal number of electrons number of electrons and protons.and protons.

An atom that has lost An atom that has lost electrons is positively electrons is positively charged, while the charged, while the atom that has gained atom that has gained electrons is negatively electrons is negatively charged.charged.

Ionic CompoundsIonic Compounds HardHard BrittleBrittle High melting & High melting &

boiling pointboiling point Transfer Transfer

electronselectrons Conduct Conduct

electricity when electricity when dissolved in waterdissolved in water

Covalent Covalent CompoundsCompounds Not hardNot hard Not brittleNot brittle Low melting and Low melting and

boiling pointboiling point Shared electronsShared electrons Doesn’t conduct Doesn’t conduct

electricity when electricity when dissolved in waterdissolved in water

HomeworkHomework

State the question into a State the question into a complete sentence formcomplete sentence form

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P. 44 &45 chapter review 1, 2, P. 44 &45 chapter review 1, 2, 6, 196, 19

Section 2 WATER AND Section 2 WATER AND SOLUTIONSSOLUTIONS

Water absorbs heat Water absorbs heat more slowly and more slowly and retains this energy retains this energy longer than many longer than many other substances do.other substances do.

Water helps cells Water helps cells maintain maintain homeostasis.homeostasis.

The hydrogen bonds The hydrogen bonds between water between water molecules cause the molecules cause the cohesion of liquid cohesion of liquid water.water.

COHESIONCOHESION An attraction An attraction

between substances between substances of the same kind.of the same kind.

Molecules at the Molecules at the surface of water are surface of water are linked together by linked together by hydrogen bonds, hydrogen bonds, which causes a which causes a condition known as condition known as surface tension.surface tension.

Surface tension Surface tension prevents the surface prevents the surface of water from of water from stretching or stretching or breaking easily.breaking easily.

ADHESIONADHESION An attraction An attraction

between different between different polar substances.polar substances.

Adhesion powers a Adhesion powers a process, called process, called capillary action, capillary action, which water which water molecules move molecules move upward through a upward through a narrow tube or narrow tube or climb up paper.climb up paper.

MixturesMixtures A substance composed A substance composed

of two or more of two or more elements that are elements that are mixed together but mixed together but not chemically not chemically combined.combined.

Unlike chemical Unlike chemical compounds, the compounds, the substances that make substances that make up a mixture can be up a mixture can be added in varying added in varying amounts.amounts.

Mixtures that are Mixtures that are made with water can made with water can be of two important be of two important typestypes

AQUEOUS SOLUTIONSAQUEOUS SOLUTIONS Solutions is a mixture Solutions is a mixture

in which one or more in which one or more substances are evenly substances are evenly distributed in an other distributed in an other substance.substance.

Solvent Solvent does the does the dissolving.dissolving.

Solute Solute is being is being dissolved.dissolved.

Ionic compounds and Ionic compounds and polar molecules polar molecules dissolve best in water.dissolve best in water.

WaterWater is the greatest is the greatest solvent because of its solvent because of its polarity.polarity.

SUSPENSIONSSUSPENSIONS

A mixture A mixture containing containing nondissolved nondissolved particles particles distributed distributed within a within a solid, liquid, solid, liquid, or gas.or gas.

Acids and BasesAcids and Bases Hydrogen ions (H+) Hydrogen ions (H+)

and hydroxide ions and hydroxide ions (OH-) form when water (OH-) form when water molecules break.molecules break.

Acid has an increased Acid has an increased number of hydrogen number of hydrogen ions lowering the pH ions lowering the pH level.level.

Bases are compounds Bases are compounds that lower the that lower the concentration of concentration of hydrogen ions.hydrogen ions.

All solutions have a pH All solutions have a pH values between 0-14.values between 0-14.

Below 7 is an acid. Below 7 is an acid. Above 7 is a base.Above 7 is a base.

pH scalepH scale Each whole number represents a Each whole number represents a

factor of 10 on the scale factor of 10 on the scale pH value of 5 has 100 times as many pH value of 5 has 100 times as many

hydrogen ions as one with a pH hydrogen ions as one with a pH value of 7value of 7

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Section review p. 33 questions 1-Section review p. 33 questions 1-55

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Table 2.1 Naturally Occurring Elements in the Human Body

Section 3Section 3CHEMISTRY OF CELLSCHEMISTRY OF CELLS

Body is Body is composed of composed of mostly water mostly water and organic and organic compounds.compounds.

Organic Organic compounds compounds contain carbon contain carbon , hydrogen, , hydrogen, and oxygen.and oxygen.

Four classes Four classes of organic of organic compounds: compounds: lipids, lipids, proteins, proteins, carbohydratecarbohydrates, and nucleic s, and nucleic acids.acids.

95% of all 95% of all known known compounds compounds contain carboncontain carbon

CARBOHYDRATESCARBOHYDRATES are a key source of are a key source of

energy for the cell (4 energy for the cell (4 calories per gram)calories per gram)

Building blocks are Building blocks are monosaccharide's monosaccharide's (single sugar) ex. (single sugar) ex. Glucose, fructose, & Glucose, fructose, & galactose (ose) Cgalactose (ose) C66HH1212OO66

Disaccharides - 2 sugars Disaccharides - 2 sugars -table sugar - sucrose-table sugar - sucrose

(1 glucose & 1 (1 glucose & 1 fructose)fructose)

Lactose Milk sugar– 1 Lactose Milk sugar– 1 glucose & 1 galactoseglucose & 1 galactose

CC1212HH2222OO1111

Carbon has four Carbon has four valence valence electrons and electrons and makes covalent makes covalent bonds, it can bonds, it can form molecules form molecules that are long that are long chains. There chains. There are several are several different kinds of different kinds of these we will be these we will be discussing: discussing: hydrocarbonshydrocarbons, , carbohydratescarbohydrates, , lipidslipids, , proteinsproteins, , and and DNADNA. .

A functional group is a group of atoms of a particular arrangement that gives the entire molecule certain characteristics. Functional groups are named according to the composition of the group. For example, COOH is a carboxyl group.

Structural Formula vs Structural Formula vs Chemical FormulaChemical Formula

Structural FormulaStructural Formula – –shows not only kinds shows not only kinds & numbers of atoms, & numbers of atoms, but arrangementbut arrangement

Chemical FormulaChemical Formula– – show kinds and show kinds and numbers of atomsnumbers of atoms

IsomersIsomers - having - having same chemical same chemical formula, but formula, but different structural different structural formulasformulas

PolysaccharidesPolysaccharides is is a macromolecule a macromolecule function as function as storehouses of the storehouses of the energy contained in energy contained in sugars. Starch sugars. Starch made by plants and made by plants and glycogen made by glycogen made by animals are animals are examples.examples.

CelluloseCellulose is a is a polysaccharide that polysaccharide that provides structural provides structural support for plants support for plants and humans can not and humans can not digest it. It is digest it. It is considered fiber in considered fiber in our dietour diet

MacromoleculeMacromolecule A very large molecule, A very large molecule,

such as a polymer or such as a polymer or protein, consisting of protein, consisting of many smaller many smaller structural units linked structural units linked together. Also called together. Also called supermolecule supermolecule oror polymerpolymer..

Upper right - tailpin Upper right - tailpin bacterial virus T7 bacterial virus T7 punctures punctures E. coli E. coli cell cell wallwall

Reactions of Biological Reactions of Biological CompoundsCompounds Condensation Condensation

ReactionsReactions also also called called dehydration dehydration synthesissynthesis or or anabolism– anabolism– when when smaller molecules smaller molecules are bonded together are bonded together to make large to make large molecules, water is molecules, water is given offgiven off

HydrolysisHydrolysis or or CatabolismCatabolism – – breaking down large breaking down large molecules to smaller molecules to smaller molecules by adding molecules by adding waterwater

http://nhscience.lonestar.edu/biol/http://nhscience.lonestar.edu/biol/dehydrat/dehydrat.htmldehydrat/dehydrat.html

Dehydration synthesisDehydration synthesis HydrolysisHydrolysis

LipidsLipids Lipids are nonpolar Lipids are nonpolar

molecules.molecules. Fats, steroids, waxes, and Fats, steroids, waxes, and

phospholipids (Found in phospholipids (Found in cell membrane)cell membrane)

Fats store energy.(9 Fats store energy.(9 calories per gram)calories per gram)

Saturated fattySaturated fatty acids are acids are generally solid at room generally solid at room temperature – mostly temperature – mostly animalanimal

Unsaturated fattyUnsaturated fatty acids acids are generally liquid at are generally liquid at room temp. mostly plantsroom temp. mostly plants

Fatty acid is the basic Fatty acid is the basic building block of building block of lipidslipids

Glycerol is a trihydric Glycerol is a trihydric alcohol (containing alcohol (containing three three -OH-OH hydroxyl hydroxyl groups) that can groups) that can combine with up to combine with up to three fatty acids to three fatty acids to form monoglycerides, form monoglycerides, diglycerides, and diglycerides, and triglyceridestriglycerides

ProteinProtein is usually a large is usually a large

molecule formed by linked molecule formed by linked smaller molecules called smaller molecules called amino acids. amino acids. (4 calories per (4 calories per gram)gram)

Amino acids are the Amino acids are the building blocks of building blocks of proteins.proteins.

There are 20 different There are 20 different amino acids found in amino acids found in proteins.proteins.

Proteins can be enzymes Proteins can be enzymes which promote chemical which promote chemical reactions.reactions.

Collagen found in skin, Collagen found in skin, ligaments, tendons, & ligaments, tendons, & bones.bones.

Humans can produce Humans can produce 10 of the 20 amino 10 of the 20 amino acidsacids

do not have all the do not have all the enzymes required for enzymes required for the biosynthesis of the biosynthesis of all of the amino all of the amino acids.acids.

Bonds between Bonds between amino acids are amino acids are called peptide bondscalled peptide bonds

NUCLEIC ACIDSNUCLEIC ACIDS A nucleic acid is a long A nucleic acid is a long

chain of smaller molecules chain of smaller molecules called called nucleotide.nucleotide.

A nucleotide has three A nucleotide has three parts: sugar, a base, and a parts: sugar, a base, and a phosphate group.phosphate group.

Two types of nucleic acids: Two types of nucleic acids: DNA- deoxyribonucleic acid DNA- deoxyribonucleic acid consists of two strands of consists of two strands of nucleotides spiral around nucleotides spiral around each othereach other

Chromosomes contain long Chromosomes contain long strands of DNA, which strands of DNA, which stores heredity informationstores heredity information..

RNA ribonucleic RNA ribonucleic acid, single strand of acid, single strand of nucleotides.nucleotides.

RNA plays many key RNA plays many key roles in the roles in the manufacture of manufacture of proteins.proteins.

ATPATP – adenosine – adenosine triphosphate – food triphosphate – food energy is temporarily energy is temporarily stored in ATPstored in ATP

Cells need a steady Cells need a steady supply of ATP to supply of ATP to function.function.

HOMEWORKHOMEWORK Restate the question in complete Restate the question in complete

sentence formsentence form

SECTION 3 PAGE 37 quest 1-5SECTION 3 PAGE 37 quest 1-5

Chapter review p. 44 & 45 quest. 8,9, Chapter review p. 44 & 45 quest. 8,9, 13, 1713, 17

STP 1-3STP 1-3 Bonus quest. 18Bonus quest. 18

Section4 Energy and Chemical Section4 Energy and Chemical ReactionsReactions Energy is the ability to Energy is the ability to

move or change matter. move or change matter. (many forms)(many forms)

Energy can be stored or Energy can be stored or released by chemical released by chemical reactions.reactions.

Chemical reaction is a Chemical reaction is a process during which process during which chemical bonds between chemical bonds between atoms are broken.atoms are broken.

Starting materials called Starting materials called reactants.reactants.

Newly formed substance Newly formed substance is called is called products.products.

EnergyEnergy is either is either released or released or absorbed during a absorbed during a chemical reaction.chemical reaction.

MetabolismMetabolism is the is the term used to term used to describe all of the describe all of the chemical chemical reactions that reactions that occur within an occur within an organism.organism.

Types of chemical Types of chemical reactionsreactions

An An exothermic exothermic reactionreaction is a is a chemical reaction chemical reaction that releases that releases energy in the form energy in the form of heat.. of heat..

An endothermic An endothermic reaction is any chemical reaction is any chemical reaction that absorbs reaction that absorbs heat from its heat from its environment. environment.

These examples could These examples could be written as chemical be written as chemical reactions, but are more reactions, but are more generally considered to generally considered to be endothermic or heat-be endothermic or heat-absorbing processes: absorbing processes:

melting ice cubes melting ice cubes melting solid salts melting solid salts evaporating liquid water evaporating liquid water

converting frost to converting frost to water vapor water vapor (melting, boiling, (melting, boiling, and evaporation in and evaporation in general are general are endothermic endothermic processes) processes)

splitting a gas splitting a gas molecule molecule

cooking an egg cooking an egg

Activation EnergyActivation Energy The energy needed to The energy needed to

start start

a chemical reaction is a chemical reaction is called called Activation Activation Energy.Energy.

EnzymesEnzymes are are substances that substances that increase the speed of increase the speed of chemical reactions.chemical reactions.

Act as Act as catalysts catalysts which which reduces activation reduces activation energy.energy.

Most enzyme-assisted Most enzyme-assisted reactions are reactions are reversiblereversible..

Enzyme SpecificityEnzyme Specificity SubstrateSubstrate is a is a

substance on which substance on which an enzyme acts an enzyme acts during a chemical during a chemical reaction.reaction.

An enzyme’s shape An enzyme’s shape determines its determines its activity. activity.

Active sitesActive sites is one is one or more deep folds or more deep folds on an enzyme’s on an enzyme’s surfacesurface

Factors in Enzyme Factors in Enzyme ActivityActivity Any factor that Any factor that

changes the shape changes the shape of an enzyme can of an enzyme can affect the enzyme’s affect the enzyme’s activityactivity

Temperature and Temperature and pH level are some pH level are some factors that affect factors that affect enzyme activity.enzyme activity.

Another limiting Another limiting factor is amount of factor is amount of available enzymeavailable enzyme

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