Chemistry of LifeChemistry of Life

What’s the Matter?What’s the Matter?All of the materials around you are made up of All of the materials around you are made up of

matter. You are made up of matter, as are the matter. You are made up of matter, as are the chair you sit on and the air you breathe. chair you sit on and the air you breathe.

1. Give an example of solid matter.1. Give an example of solid matter.

2. Give an example of liquid matter.2. Give an example of liquid matter.

3. Give an example of gaseous matter.3. Give an example of gaseous matter.

4. Is all matter visible? 4. Is all matter visible?

5. Does all matter take up space?5. Does all matter take up space?

Matter & MassMatter & Mass

Matter: Anything that has mass and takes Matter: Anything that has mass and takes up spaceup space

Mass: Measure of the amount of matter an Mass: Measure of the amount of matter an object contains object contains

The Nature of MatterThe Nature of Matter

Atoms Atoms Smallest part of an elementSmallest part of an element

From Greek work From Greek work atomos = atomos = Unable to be cut Unable to be cut or indivisible or indivisible

Made up of 3 partsMade up of 3 parts

Protons (+) charge Protons (+) charge nucleus nucleus Electrons (-) charge Electrons (-) charge electron cloud electron cloud Neutron (no charge) Neutron (no charge) nucleus nucleus

ElementElement

Pure substance, contains only 1 type of atomPure substance, contains only 1 type of atom

More than 100, but only about 2 dozen are found in More than 100, but only about 2 dozen are found in living things.living things.

4 elements that make up 96% of living matter4 elements that make up 96% of living matter

H (hydrogen), O (Oxygen), N (Nitrogen), C (Carbon)H (hydrogen), O (Oxygen), N (Nitrogen), C (Carbon)

6 most common - CHNOPS6 most common - CHNOPS

Atomic #Atomic # Atomic SymbolAtomic Symbol Element NameElement Name Atomic MassAtomic Mass

Atomic NumberAtomic NumberNumber of protons and or electronsNumber of protons and or electrons

Atomic # = pAtomic # = p++ = e = e--

Atomic Mass or Mass NumberAtomic Mass or Mass NumberNumber of protons + number of neutronsNumber of protons + number of neutrons

pp+ + + n = mass number+ n = mass numbern= mass number – p+n= mass number – p+

PracticePractice

1.1. What is the atomic # of Carbon?What is the atomic # of Carbon?2.2. How many electrons does Boron have?How many electrons does Boron have?3.3. What is the mass number of Neon?What is the mass number of Neon?4.4. How many protons does Helium have?How many protons does Helium have?5.5. How many neutrons does Chlorine How many neutrons does Chlorine

have?have?

IsotopesIsotopes

An element with the same number of An element with the same number of protons but different number of neutronsprotons but different number of neutrons

IsotopesIsotopes

Isotopes of CarbonIsotopes of Carbon

Nonradioactive carbon-12 Radioactive carbon-14Nonradioactive carbon-13

6 electrons6 protons6 neutrons

6 electrons6 protons7 neutrons

6 electrons6 protons8 neutrons

Radioactive IsotopesRadioactive Isotopes

Unstable nucleusUnstable nucleus Break down at a constant rateBreak down at a constant rate Used to date rocks & fossilsUsed to date rocks & fossils Used as a cancer treatmentUsed as a cancer treatment Used to kill bacteriaUsed to kill bacteria Used as “tracers” follow movement of Used as “tracers” follow movement of

substances in an organismsubstances in an organism

PET (positron emission tomography) SCANSPET (positron emission tomography) SCANShttp://www.youtube.com/watch?v=GHLBcCv4rqk

Other scans using radioactive Other scans using radioactive tracerstracers

A hepatobiliary (HIDA) scan is an imaging procedure used to diagnose problems in the liver, gallbladder and bile ducts.

http://www.youtube.com/watch?v=VDihrC1RnYE

Chemical CompoundsChemical CompoundsCompoundCompound

Chemical combination of 2 or more different Chemical combination of 2 or more different elementselements

Composition of compound is shown by molecular Composition of compound is shown by molecular formulaformula

Ex] HEx] H22OO

Physical & chemical properties of a compound are Physical & chemical properties of a compound are very different than those of the elements that very different than those of the elements that

make it upmake it upEX] NaClEX] NaCl

Chemical BondsChemical Bonds Atoms in compounds are held together by Atoms in compounds are held together by

chemical bondschemical bonds Bonds involve electrons in outer energy Bonds involve electrons in outer energy

levellevel Outer most energy level is known as the Outer most energy level is known as the

valence shellvalence shell11stst 2 electrons 2 electrons22ndnd 8 electrons 8 electrons33rdrd 18 electrons 18 electrons

Valence shell holds a maximum of 8 Valence shell holds a maximum of 8 electronselectrons

1) Covalent Bonds1) Covalent BondsElements Elements shareshare electrons for stability. electrons for stability.Number of bonds? Use “HONC-1234”Number of bonds? Use “HONC-1234”Quite strong… takes a lot of energy to break Quite strong… takes a lot of energy to break them!them!– But you CAN, because we burn fat, recycle But you CAN, because we burn fat, recycle

materials… plants break bonds in CO2 and H20 to materials… plants break bonds in CO2 and H20 to rework them into complex sugarsrework them into complex sugars

Ex: HEx: H22O, COO, CO22, C, C66HH1212OO6 6 (glucose) (glucose) – Some polar, some non polar…. Some polar, some non polar….

Covalent BondCovalent Bond

Molecular structures of Molecular structures of covalent compoundscovalent compounds

GlucoseGlucoseHemoglobinHemoglobin

DNADNA

(polar covalent?)(polar covalent?)Oxygen is more greedy for electrons Oxygen is more greedy for electrons than hydrogen, so it has more ‘custody’ than hydrogen, so it has more ‘custody’ Creates partially negative and positive Creates partially negative and positive areasareas

2) Ionic Bonds2) Ionic Bondsinvolve the involve the transfertransfer of electrons. of electrons.Whether they donate or receive is determined by Whether they donate or receive is determined by the number of electrons in the valence shell.the number of electrons in the valence shell.– Cation:Cation: positive (b/c it lost e positive (b/c it lost e--))– Anion:Anion: negative (b/c it stole e negative (b/c it stole e--))– Due to extreme differences in electronegativityDue to extreme differences in electronegativity

Ex: NaCl (table salt) or KI (a stain) or CaCOEx: NaCl (table salt) or KI (a stain) or CaCO33 (in (in seashells)seashells)

These molecules dissolve easily in water, blood, These molecules dissolve easily in water, blood, cytoplasm, tree sap… etc. cytoplasm, tree sap… etc.

Sodium atom (Na) Chlorine atom (Cl) Sodium ion (Na+) Chloride ion (Cl-)

Transferof electron

Protons +11Electrons -11Charge 0

Protons +17Electrons -17Charge 0

Protons +11Electrons -10Charge +1

Protons +17Electrons -18Charge -1

Figure 2-3 Ionic Bonding

Like & Unlike chargesLike & Unlike charges

3) Hydrogen bonds3) Hydrogen bondsUsually between Usually between waterwater molecules molecules (makes them cohesive)(makes them cohesive)

Causes:Causes:– Ice’s low densityIce’s low density– Sweat’s cooling powerSweat’s cooling power– Plants drinking ‘against gravity’Plants drinking ‘against gravity’– Insects to walk on waterInsects to walk on water

IceIce CohesionCohesion

SweatSweat

3) Hydrogen bonds3) Hydrogen bonds

Relative Relative Bond Bond

StrengthsStrengths

Chemistry SummaryChemistry SummaryEverything around you is made of matter Everything around you is made of matter composed of atomscomposed of atoms

Atoms - nucleus of protons and neutrons Atoms - nucleus of protons and neutrons surrounded by a cloud of electrons.surrounded by a cloud of electrons.

Elements have different # p+ , e-, and n0Elements have different # p+ , e-, and n0

Isotopes have the same # p+ but diff # n0Isotopes have the same # p+ but diff # n0

Chemistry SummaryChemistry SummaryCompounds have 2 or more elementsCompounds have 2 or more elementsBonds form from interaction of outer e-Bonds form from interaction of outer e-

Covalent bonds- strongest - share e-Covalent bonds- strongest - share e-Ionic bonds – medium – trade e-Ionic bonds – medium – trade e-– Water solubleWater soluble

Hydrogen bonds – weak – interaction b/w Hydrogen bonds – weak – interaction b/w polar moleculespolar molecules