The Chemistry of

Life

•Is the basic Is the basic unit of unit of mattermatter

•Is made up Is made up of the of the Proton, Proton, Neutron, and Neutron, and ElectronElectron

An Atom An Atom consists ofconsists ofAn Atom An Atom

consists ofconsists of

ElectronElectronCloud Cloud

ElectronElectronCloud Cloud

NeutralNeutralNeutralNeutral

• The atomic number of carbon is The atomic number of carbon is _______________._______________.

• So carbon has ________ protons So carbon has ________ protons and electrons.and electrons.

• The protons and neutrons are The protons and neutrons are found in the ______________.found in the ______________.

• It’s the number of ____________ It’s the number of ____________ that determines which that determines which kindkind of atom of atom it is. it is.

• Are pure substances that consist Are pure substances that consist entirely of entirely of oneone type of atom type of atom

• More than 100 elements are knownMore than 100 elements are known

• Represented by a letter symbolRepresented by a letter symbol

• Substances formed by the Substances formed by the chemical combination of chemical combination of twotwo or more elements.or more elements.

• What is NaCl?What is NaCl?

• How about HHow about H220?0?

• IonicIonic: When electrons are : When electrons are transferred from one atom to transferred from one atom to another.another.

• If an atom loses an electron it has If an atom loses an electron it has a _________ charge.a _________ charge.

• If an atom gains an electron it If an atom gains an electron it has a _________ charge.has a _________ charge.

Bonding of Sodium & Bonding of Sodium & Chlorine AtomsChlorine Atoms

• Electrons are Electrons are sharedshared not not transferredtransferred

• Electrons travel in the orbitals of Electrons travel in the orbitals of bothboth atoms atoms

• Covalent bonds form Covalent bonds form moleculesmolecules• The The moleculemolecule is the smallest unit is the smallest unit

of most compoundsof most compounds

The Water The Water MoleculeMolecule• A water A water

molecule is molecule is POLAR POLAR because because there is an there is an unevenuneven distribution distribution of electrons.of electrons.

• When there are oppositely When there are oppositely charged ends in an atomcharged ends in an atom

The Hydrogen The Hydrogen BondBond• NegativeNegative and and positivepositive ends of ends of

molecules are attractedmolecules are attracted• The bonds formed are The bonds formed are

HYDROGEN HYDROGEN bondsbonds• Occur between water Occur between water

moleculesmolecules• Weakest of all the bondsWeakest of all the bonds

pH scalepH scale measures the measures the concentration of H+ ions in a concentration of H+ ions in a

solutionsolution

•Ranges from 0-14Ranges from 0-14• At a pH of 7, the At a pH of 7, the concentrations of H+ and concentrations of H+ and OH- ions are equalOH- ions are equal

•Solutions Solutions belowbelow 77 are are acidicacidic because they because they have more H+ ions than have more H+ ions than pure waterpure water

• Solutions Solutions above 7above 7 are called are called

basicbasic, because they have , because they have less H+ ions than pure waterless H+ ions than pure water

• Substances that prevent sharp Substances that prevent sharp sudden changes in pHsudden changes in pH

• The body helps maintain The body helps maintain homeostasishomeostasis by using by using buffersbuffers

Blood pH is 6.5-Blood pH is 6.5-7.57.5

What’s so great about Carbon?What’s so great about Carbon?• It has 4 valence electrons…so it It has 4 valence electrons…so it

bonds with many other elements!bonds with many other elements!

• It can also bond with itself, forming It can also bond with itself, forming long chains and ringslong chains and rings

•Hydrogen•Carbon•Nitrogen•Oxygen•Phosphorus •Sulfur

• MonomersMonomers bond together bond together to make a to make a polymerpolymer

• Like a chain Like a chain of moleculesof molecules

•Carbohydrates•Lipids•Nucleic acids•Proteins

CarbohydratesCarbohydrates• Carbohydrates are made up Carbohydrates are made up

of C, H, and O, with a ratio of of C, H, and O, with a ratio of 1:2:1.1:2:1.

Carb Carb Function?Function?• Main source of energy for Main source of energy for

all cellular activityall cellular activity• Provides structure for Provides structure for

plants and animalsplants and animals• Humans store extra sugar Humans store extra sugar

as glycogenas glycogen

• Single sugar moleculeSingle sugar molecule• Smallest is glucoseSmallest is glucose• Examples include:Examples include:

–GlucoseGlucose–GalactoseGalactose–FructoseFructose

LIPIDSLIPIDS•Not soluble in H2O Not soluble in H2O (hydrophobic)(hydrophobic)

•Mostly carbon and Mostly carbon and hydrogen hydrogen

•Include fats, oils, Include fats, oils, steroids, and waxessteroids, and waxes

Lipid Function?Lipid Function?

• Form when a glycerol Form when a glycerol molecule combines with 3 molecule combines with 3 fatty acidsfatty acids

• Saturated (no carbon-Saturated (no carbon-carbon double bonds) fat carbon double bonds) fat is bad for you!is bad for you!

Nucleic Acids• Contain hydrogen, oxygen, Contain hydrogen, oxygen,

nitrogen, carbon, and nitrogen, carbon, and phosphorousphosphorous

• Are polymers assembled from Are polymers assembled from nucleotides.nucleotides.

• Store and transmit genetic Store and transmit genetic informationinformation

• Include RNA & DNAInclude RNA & DNA

•5-carbon sugar5-carbon sugar

•phosphate groupphosphate group

•nitrogenous basenitrogenous base

ProteinsProteins•contain hydrogen, nitrogen, contain hydrogen, nitrogen, carbon, and oxygencarbon, and oxygen

•are polymers of amino acidsare polymers of amino acids•are among the most diverse are among the most diverse macromoleculesmacromolecules

• Amino Acids are

Protein Protein function?function?• Control the rate of reactions Control the rate of reactions

and regulate cell processesand regulate cell processes

• Form bone and muscleForm bone and muscle

• Transport substances into Transport substances into or out of cellsor out of cells

• Help to fight diseaseHelp to fight disease

Levels of organizationLevels of organization• 11stst is sequence of amino is sequence of amino

acids in a protein chainacids in a protein chain

• 22ndnd is if the amino acids are is if the amino acids are twisted or foldedtwisted or folded

• 33rdrd is if the chain is folded is if the chain is folded

MonosaccharideMonosaccharide MonosaccharideMonosaccharide

AlcoholAlcohol 3 Fatty Acids3 Fatty Acids

Amino AcidAmino Acid Amino AcidAmino Acid

2.4 Chemical Reactions & Enzymes 2.4 Chemical Reactions & Enzymes

• Chemical reactions change one Chemical reactions change one set of chemicals into anotherset of chemicals into another

• Reactants ProductsReactants Products

• Chem rxns always involve Chem rxns always involve bond changes!bond changes!

Paper will only burn Paper will only burn if lit with a match!if lit with a match!

•Are Are proteinsproteins that act that act as biological catalystsas biological catalysts

•Speed up chemical reactionsSpeed up chemical reactions•Lower activation energyLower activation energy•Are very specific, only work Are very specific, only work

with certain substrateswith certain substrates

• Regulate chemical Regulate chemical pathwayspathways

• Make materials for cellsMake materials for cells

• Release energyRelease energy

• Transfer informationTransfer information

Enzymes Enzymes help make help make or break or break bondsbonds

• Enzymes provide a site Enzymes provide a site where reactants can be where reactants can be brought together to reactbrought together to react

• This reduces the energy This reduces the energy needed for the reactionneeded for the reaction

• The reactants of enzyme-The reactants of enzyme-catalyzed reactions are catalyzed reactions are known asknown as substratessubstrates

ACTIVACTIVE SITEE SITE

Do enzymes require certain Do enzymes require certain conditions?conditions?

At what At what temp. do temp. do you think you think

enzymes in enzymes in the human the human body work body work best????best????