Picture Guide to Chapter 4

Chapter 2The Chemistry of Life

2-1: The Nature of MatterAtoms (Basic unit of matter)Subatomic particles that make up atoms are protons, neutrons, and electrons2Subatomic particlesProtons - Neutrons - Electrons - Positively charged (+)Not charged (neutral)Negatively charged (-)Bind together to form the nucleus

ElectronsProtonsNeutronsNucleusElement - a pure substance that consists of just one type of atomIsotope - atoms of the same element that differ in the number of neutrons they contain

Nonradioactive carbon-12Nonradioactive carbon-13Radioactive carbon-146 electrons6 protons6 neutrons6 electrons6 protons8 neutrons6 electrons6 protons7 neutronsElements and IsotopesRadioactive isotopesCan be dangerousCan be used practicallyRadioactive datingTreat cancerKill bacteria

Chemical Compounds / BondsCompound - A substance formed by the chemical combination of two or more elements in definite proportionsEx) H2O, NaCl

Ionic Bonds - Formed when one or more electrons are transferred from one atom to another

Sodium atom (Na) Chlorine atom (Cl) Sodium ion (Na+) Chloride ion (Cl-)Transferof electronProtons +11Electrons -11Charge 0Protons +17Electrons -17Charge 0Protons +11Electrons -10Charge +1Protons +17Electrons -18Charge -1If an atom loses an electron it becomes positive ( Na + )If an atom gains an electron it becomes negative ( Cl - ) }Ions2-2: Properties of WaterCovalent Bonds - Forms when electrons are shared between atoms

Much of our planet is covered in water

Water is necessary for life to exist

If life exists on other planets, there most likely is water present

Water has many properties that make life possiblePolarity

(-)(+)The oxygen atom has a stronger attraction for electrons(+)Hydrogen BondsBecause of waters partial charges, they can attract each other and create hydrogen bonds

Not as strong as covalent or ionic bonds

Waters ability to create multiple hydrogen bonds gives it many special properties

Cohesion - Attraction between molecules of the same substance

Adhesion Attraction between molecules of different substancesSolutions and SuspensionsMixture - Material composed of two or more elements or compounds that are physically mixed but not chemically combined

Solutions - Mixture of two or more substances in which the molecules are evenly distributed

Suspension - Mixture of water and non-dissolved materials (separate into pieces so small, they never settle out)

The pH scaleIndicates the concentration of hydrogen ions in a solution

Acid - Any compound that forms H+ (hydrogen) ions in solutionBase - A compound that produces OH- (hydroxide) ions in solution

NeutralAcidBase2- 3: Carbon CompoundsWhat makes carbon special?Carbon has 4 valence electrons and can bond with various elementsCan bond with other carbons forming long chains and rings more complex and larger molecules

MethaneAcetyleneButadieneBenzeneIsooctaneMacromolecules giant moleculesSmaller units called monomers join together to form the larger macromolecules called polymers.There are 4 groups of macromoleculesCarbohydratesLipidsNucleic AcidsProteinsCarbohydratesContain carbon (C ), hydrogen (H), and oxygen (O) atoms in a ratio of 1:2:1 [ C6H12O6 ]Are a major source of energyExamples include sugar, starch, monosaccharides and polysaccharides StarchGlucose

LipidsMade mostly from C and HUsed to store energyNot soluble in waterExamples include fats, oils, and waxes

LipidGlycerolFatty Acids Nucleic AcidsMacromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus

Double HelixNucleotidesConsists of 3 parts: 5-carbon sugar, phosphate group and nitrogen base

Nitrogen Base5-Carbon SugarPhosphate group2 kinds of nucleic acidsRNA (ribonucleic acids) contains sugar ribose

DNA (deoxyribonucleic acid) contains sugar deoxyriboseProteinsPolymers made of amino acids containing H, O, C, and N

Control rates of reaction, regulate cell processes, form bones and muscles, transport substances in and out of cells, fight diseaseAmino Acids

General structureAlanineSerineCarboxyl groupMore than 20 different amino acids, can join to any other amino acid

The instructions for arranging amino acids into many different proteins are stored in DNA

Each protein has a specific role

The shape of proteins can be very important

ProteinsAmino Acids2- 4: Chemical Reactions and EnzymesChemical Reactions - A process that changes or transforms one set of chemicals into another

Reactants - Elements or compounds that enter into a reaction

Products - Elements or compounds produced by a chemical reaction

Example Reaction: Getting rid of carbon dioxideIn the blood

In the lungsCO2 + H20 H2CO3 (carbonic acid)H2CO3 CO2 + H2OReleased as you breatheEnergy in reactions

Energy-Absorbing Reaction Energy-Releasing ReactionProductsProductsActivation energyActivation energyReactantsReactantsActivation EnergyThe energy that is needed to get a reaction started

Catalysts are chemicals that speed up a chemical reaction by lowering activation energyEnzymes:Biological catalysts (proteins)Speed up reactions in cellsVery specificNamed for the reaction is catylzesEnzyme names always end in -ase Substrates:The reactants of enzyme catalyzed reactionsThe active site of the enzyme and the substrate have complementary shapesFit like a lock and key

Enzyme Action

Enzyme substrate complex