CHEMISTRY COMES ALIVECHEMISTRY COMES ALIVE

Chapter 2Chapter 2

Definition of ConceptsDefinition of Concepts

MatterMatter = anything that occupies space = anything that occupies space and has mass.and has mass.

SolidSolid

LiquidLiquid

GasGas

EnergyEnergy = the ability to do work = the ability to do workPotential energyPotential energy

Kinetic energyKinetic energy

COMPOSITION OF MATTERCOMPOSITION OF MATTER

Matter is composed of Matter is composed of elements, 92 of which elements, 92 of which occur naturally.occur naturally.

ElementsElements cannot be cannot be broken down or subdivided broken down or subdivided by ordinary chemical by ordinary chemical means.means.

98% of the body is 98% of the body is composed of the elements composed of the elements CHNOPSCHNOPS

COMPOSITION OF MATTERCOMPOSITION OF MATTERAtomsAtoms = smallest indivisible unit of an = smallest indivisible unit of an element.element.

MoleculeMolecule = two or more atoms of the = two or more atoms of the same element held together by chemical same element held together by chemical bondsbonds

CompoundsCompounds = two or more atoms of = two or more atoms of different elements held together by different elements held together by chemical bonds.chemical bonds.

ATOMIC STRUCTUREATOMIC STRUCTURE

PLANETARY MODELSPLANETARY MODELS

PERIODIC CHARTPERIODIC CHART

INERT ELEMENTSINERT ELEMENTS

ACTIVE ELEMENTSACTIVE ELEMENTS

RULES OF BONDINGRULES OF BONDING

Atoms in the periodic chart are said to be Atoms in the periodic chart are said to be neutral atomsneutral atoms = that is they have no = that is they have no charge because they possess the same charge because they possess the same number of protons (+) as electrons (-).number of protons (+) as electrons (-).

IonsIons = charged particles because of = charged particles because of uneven numbers of protons and electrons.uneven numbers of protons and electrons.– CationCation = positively charged = positively charged– AnionAnion = negatively charged = negatively charged

IONIC BONDSIONIC BONDS

COVALENT BONDSCOVALENT BONDS

COVALENT BONDSCOVALENT BONDS

COVALENT BONDSCOVALENT BONDS

POLAR versus NON-POLARPOLAR versus NON-POLAR

HYDROGEN BONDSHYDROGEN BONDS

BIOLOGICALLY IMPORTANT BIOLOGICALLY IMPORTANT COMPOUNDSCOMPOUNDS

InorganicInorganic compoundscompounds = those that lack = those that lack carbon such as water, salt, hydrochloric carbon such as water, salt, hydrochloric acid, etc.acid, etc.

OrganicOrganic compoundscompounds = those that contain = those that contain carbon such as carbohydrates, lipids, carbon such as carbohydrates, lipids, proteins, etc.proteins, etc.

INORGANIC COMPOUNDSINORGANIC COMPOUNDS

WaterWater is the most is the most important biological important biological inorganic compound.inorganic compound.– PolarPolar– High heat capacityHigh heat capacity– High heat of vaporizationHigh heat of vaporization– Exhibits adhesion and Exhibits adhesion and

cohesioncohesion– Liquid water is denser than Liquid water is denser than

solid watersolid water– CushioningCushioning

INORGANIC COMPOUNDSINORGANIC COMPOUNDS

ElectrolytesElectrolytes = any = any substance that substance that disassociates in solution disassociates in solution to form ions that are able to form ions that are able to conduct electrical to conduct electrical currents.currents.– SaltsSalts– BasesBases– NeutralsNeutrals– AcidsAcids– BuffersBuffers

SALTSSALTS

Electrolyte that disassociates to form two Electrolyte that disassociates to form two of the most notable ions in current of the most notable ions in current conduction.conduction.

NaClNaCl NaNa++ + Cl + Cl--

ACIDSACIDS

Release H+ ionsRelease H+ ions

Considered to be proton donorsConsidered to be proton donors

pH of less than 7.0pH of less than 7.0

Example:Example:

HCl HCl HH++ ++ ClCl--

BASESBASES

Release OH- ionsRelease OH- ions

Considered to be proton acceptorsConsidered to be proton acceptors

pH greater than 7.0pH greater than 7.0

Example:Example:

NaOHNaOH NaNa++ + + OHOH--

BUFFERSBUFFERS

Buffers resist abrupt and large swings in Buffers resist abrupt and large swings in pH of body fluids by releasing hydrogen pH of body fluids by releasing hydrogen ions when pH begins to rise and also ions when pH begins to rise and also binding hydrogen ions when pH begins to binding hydrogen ions when pH begins to fall.fall.

HCl + NaHCOHCl + NaHCO33 HH22COCO33 + NaCl + NaCl

NaOH + HNaOH + H22COCO33 NaHCONaHCO33 + H + H22OO

ORGANIC COMPOUNDSORGANIC COMPOUNDS

Organic compounds contain carbon units put Organic compounds contain carbon units put together by covalent bonds.together by covalent bonds.

There are four types of organic compounds:There are four types of organic compounds:– CarbohydrateCarbohydrate– LipidLipid– ProteinProtein– Nucleic acidNucleic acid

CARBOHYDRATESCARBOHYDRATES

CARBOHYDRATESCARBOHYDRATES

CARBOHYDRATESCARBOHYDRATES

LIPIDSLIPIDS

LIPIDSLIPIDS

LIPIDSLIPIDS

PROTEINSPROTEINS

PROTEINSPROTEINS

PROTEINSPROTEINS

PROTEINSPROTEINS

NUCLEIC ACIDSNUCLEIC ACIDS

NUCLEIC ACIDSNUCLEIC ACIDS