2.1

9 - 25 - 06

Atom

• Simplest particle of anelement

• Properties of atomdetermine the structure andproperties of elements

3 parts of an atom

• Proton

• Neutron

• Electrons

• Positive - nucleus

• Neutral - nucleus

• Negative -orbitals outsidethe nucleus

Atoms

Elements

• Pure substances

• Cannot be broken down intosimpler kind of matter

• 100+ elements

• CHON (Carbon, Hydrogen,Oxygen, Nitrogen) -- 90% ofliving things

Balance

• Number of p+ isbalanced by an equalnumber of e-

• Net charge of an atomis ZERO

Exception

• Some elements– different number ofneutrons– ISOTOPES

• Same properties

Compound

• Combination of two ormore elements

• Chemical formula

• H20– 2 hydrogens : 1 oxygen

ChemicalFormula

1.NaCl2.CO2

3.H2CO3

What are theelementsinvolved?

How many ofeachelement? 4. Fe2O3

5. 8H20

1.NaCl 1-sodium, 1-chlorine

2.CO2 1-Carbon, 2-Oxygen3.H2CO3 2-Hydrogen, 1-

Carbon , 3-oxygen4. Fe2O3 2-Iron, 3-Oxygen5. 8H20 16-hydrogen, 8

oxygen

Compound

• Have different physical andchemical properties fromindividual elements

• H2 and 02 vs H20

Compound

• Go under chemical reaction– combine atoms to becomestable

• How do they stick?

Bond

• Attachment

• Glue

• Chemical Reaction (rxn)they are either broken orcreated

Bonds

• Covalent Bond

• Ionic Bond

Covalent Bonds

• Two atoms SHAREelectrons

• Example H2O

balanced

• Oxygen needs 2 moree- to be stable

• Each H needs 1 moree-

Molecule

• Simplest part of asubstance and retainsproperties

• H2 molecule = gas• H2O molecule = liquid in

room temp

IOnic Bonds

• Atom loses or gainselectrons to anotheratom

• Both atoms are stable

IOn

• Atom is no longerstable

• Has an electricalcharge

IOn

• Lose e- = positive

• Gain e- = negative

2.2

9 - 27 - 06

Polarity

• Uneven distribution ofelectrons

• Occurs between H and O inwater molecules

Hydrogen

Oxygen

Hydrogen Bonds

• Attraction of the + and -• Water molecules to be

attracted to each other• Bonds via HYDROGEN BONDs• Multiple bonds allow for

special properties

Cohesion

• Attraction betweenmolecules of the samesubstance

• Surface drawn inward

• Water beads

Adhesion

• Attraction betweenmolecules of differentsubstances

• Water and glass

mixture

• 2 or more elements (orcompounds) arePHYSICALLY mixedtogether but NOTCHEMICALLY combined

mixtures

• 2 or more compounds• One of them is water– SOLUTIONS– SUSPENSIONS

SOLUTIONS

• All components aredistributed EVENLYthroughout the solution

Sugar solution

• Solute -- what is beingdissolved?

• Solvent -- what causesthe dissolvement?

SUGAR

H20

Suspensions

• Not all materialsdissolved

• Solutes are suspended

pH Scale• Indicates concentration of H+

in solutions

• Acids -

• Basic -

• Neutral

pH Scale Foldable1. Fold paper in hot dog

2. Front - draw a pH scale

3. Front - simplify properties

a) what compound forms insolution?

b) pH values?

2.3

10 - 2 - 2006

Carbon

• 4 valence e-– forms strong covalentbonds with otherelements

• forms bonds withother C

Macromolecules

• Giant molecules

What is it made of?

What is polymerization?

Organic compounds

• 4 kinds– carbohydrates– lipids– nucleic acids– proteins

carbohydrates

• Main source of energy

• Ex: sugars

What elements make upcarbs? Ratio?

Monosaccharides

• Single sugar molecules– glucose - cell energy

– galactose - milk

– fructose - fruits

polysaccharides

• More than onemonosaccharide– glycogen - animal starch

– cellulose - plants

Lipids

• Not soluble in water

• C and H

• Fats, oil, waxes

What is the purpose oflipids?

Lipids

• One C-C double bond

– unsaturated

– polyunsaturated

• All single bonds

– saturated

Nucleic acids

• H, O, N, C, PWhat makes up thenucleotides?

What is the purpose ofnucleic acid?

Nucleic acids

What are the two kindsof nucleic acids?

What is the differencebetween the two?

proteins

• N, C, H, O• What are amino acids?• What are the differentparts of the amino acids?• How many amino acids arethere?

proteins

• Controls the rate ofreactions• Regulate cell processes• Form bones and muscles• Transports substances intoand out of cells

2.4

10/3/06

Chemicalreactions

• 2 parts

– reactants

– products

CO2 + H2O --> H2CO3

reactants

• left side of the equation

CO2 + H2O --> H2CO3

products

• right side of theequation

CO2 + H2O --> H2CO3

Energy

• release will occurspontaneously

• Absorption will notoccur without a source

Activationenergy

• amount or energyneeded to start thereaction

Catalyst

• Substance thatreduces the neededactivation energy

Enzymes

• Type of catalyst

• Help speed up

• Gives additional amountof energy

enzymes

10/4/06

Enzymes

• Type of catalyst

• Help speed up

• Gives additional amountof energy

Enzymes

• Very specific– one enzyme for aspecific reaction

• Name of enzyme isusually a hint

Enzyme substratecomplex

• Enzyme provide a placewhere reactants can bebrought together toreact• Site = lower activationenergy

Enzyme substratecomplex

• Substrates– reactants of enzyme-catalyzed reactions

Enzyme substratecomplex

• Substrates bind onenzyme at ACTIVE SITE• Lock and key

Enzyme substratecomplex

Enzyme substratecomplex

• Substrates are in activesites until reaction isover