c6-the chemistry of life

C6-The Chemistry of LifeC6-The Chemistry of Life

Biology Chp 6Biology Chp 6

Chemistry of LifeChemistry of Life

6-1 Atoms and Their Interactions6-1 Atoms and Their Interactions

6-2 6-2 Water and DiffusionWater and Diffusion

6-3 6-3 BiomoleculesBiomolecules

Atoms & Their InteractionsAtoms & Their Interactions

Everything is made of Everything is made of elements- elements- substances substances that cannot be broken down into simpler that cannot be broken down into simpler substancessubstances


Only about 25 Only about 25 elements are elements are essential to human essential to human lifelife

C, H, O & N make C, H, O & N make up 96% of a human up 96% of a human bodies mass!bodies mass!


One or two letter One or two letter symbolssymbols are are abbreviations for the abbreviations for the elements.elements.

Also listed in each Also listed in each box are the atomic box are the atomic number and the number and the atomic mass.atomic mass.


For carbon, the For carbon, the atomic numberatomic number 6 6 indicates its number indicates its number of of protons.protons.

Mass NumberMass Number = = protons +neutronsprotons +neutrons

Thus, Thus, Mass Number- Mass Number- atomic number = atomic number = number of neutronsnumber of neutrons

Atoms: Building Blocks of ElementsAtoms: Building Blocks of Elements

The center of the The center of the atom is the atom is the nucleusnucleus..– Positive protonsPositive protons– Neutral neutronsNeutral neutrons

The space around the The space around the nucleus contains nucleus contains negatively charged negatively charged electrons. electrons. (electron (electron cloud)cloud)


Protons=ElectronsProtons=Electrons

Therefore, atom is Therefore, atom is neutral overall.neutral overall.

Electron energy levelsElectron energy levels– Level 1 holds 2Level 1 holds 2– Level 2 holds 8Level 2 holds 8– Level 3 holds 8-18Level 3 holds 8-18


Isotopes Isotopes of an atom of an atom have differing have differing numbers of neutrons.numbers of neutrons.The number of The number of protons in an element protons in an element always remains the always remains the same.same.Isotopes are named Isotopes are named by the total number of by the total number of protons & neutrons protons & neutrons i.e. Carbon-14i.e. Carbon-14


Isotopes are unstable Isotopes are unstable & tend to break apart & tend to break apart giving off radiation.giving off radiation.

Carbon -14 is used to Carbon -14 is used to date things under date things under 55,000 years old by 55,000 years old by measuring the measuring the amount of C-14 left.amount of C-14 left.

Compounds & BondingCompounds & Bonding

CompoundsCompounds are are composed of 2 or composed of 2 or more different atoms more different atoms that are chemically that are chemically combined.combined.

Properties of a Properties of a compound are compound are different than the different than the elements.elements.


Atoms combine with Atoms combine with other atoms only other atoms only when it results in when it results in more stability.more stability.An atom become An atom become more stable when its more stable when its outermost energy outermost energy level is full.level is full.One way is to share One way is to share electrons by electrons by covalent covalent bonding.bonding.


Hydrogen becomes Hydrogen becomes stable by sharing its stable by sharing its atom with the other so atom with the other so that the electrons that the electrons move about both move about both nuclei.nuclei.

The attraction of The attraction of positive nuclei for positive nuclei for negative electrons negative electrons holds them together.holds them together.

Covalent Bond


A A molecule molecule is a is a group of atoms held group of atoms held together by covalent together by covalent bonds.bonds.

In water, the atoms In water, the atoms share eight electrons.share eight electrons.

Chemical formula HChemical formula H22OO


Sometimes atoms Sometimes atoms combine by gaining or combine by gaining or losing electrons (e-).losing electrons (e-).IonIon is a charged is a charged particle.particle.In salt, Na loses one In salt, Na loses one e- to Cl which has 7e- e- to Cl which has 7e- in its outer energy in its outer energy level for a total of 8 level for a total of 8 forming an forming an Ionic Ionic bond.bond.


Ionic bonds are Ionic bonds are important in biological important in biological processes such as:processes such as:– Transmission of nerve Transmission of nerve

impulsesimpulses– Muscle contractionMuscle contraction– Essential minerals for Essential minerals for

plant growthplant growth

Chemical ReactionsChemical Reactions

All chemical reactions All chemical reactions that occur in an that occur in an organism are referred organism are referred to as to as metabolism.metabolism.These reactions These reactions break down and build break down and build molecules important molecules important for their functioning.for their functioning.Chemical equations Chemical equations represent these represent these reactions.reactions.


In a chemical RXN, atoms are neither created In a chemical RXN, atoms are neither created nor destroyed.nor destroyed.Mass is conserved; atoms are rearranged from Mass is conserved; atoms are rearranged from reactants to products so that numbers of each reactants to products so that numbers of each are equal on both sides.are equal on both sides.

2Cu + O2 → 2CuO


Add coefficients to balance this equation: Add coefficients to balance this equation:

ClCl2 2 + NaBr + NaBr NaCl + Br NaCl + Br22

+ +


Add coefficients to balance this equation: Add coefficients to balance this equation:

ClCl2 2 + NaBr + NaBr NaCl + Br NaCl + Br22

ClCl2 2 + 2 NaBr + 2 NaBr 2 NaCl + Br 2 NaCl + Br22

Same number (2) of Cl Na Br on each side!Same number (2) of Cl Na Br on each side!

+ +

Cl2NaBr

Br2

Mixtures and SolutionsMixtures and Solutions

A A mixturemixture is a is a combination of combination of substances which substances which retain their own retain their own individual properties.individual properties.

They can be easily They can be easily separated.separated.


A A solution solution is a is a mixture with the mixture with the solute distributed solute distributed evenly throughout the evenly throughout the solvent. solvent.

Simply put, one Simply put, one substance is substance is dissolved in the other dissolved in the other so that it won’t settle so that it won’t settle out.out.


Solutions are Solutions are important to life:important to life:Sugar & mineral ions Sugar & mineral ions are dissolved in waterare dissolved in waterConcentrations of Concentrations of solutions must be solutions must be regulatedregulatedChemical RxNs only Chemical RxNs only happen in certain happen in certain conditionsconditions

Acids and BasesAcids and Bases

Reactions depend on available energy, Reactions depend on available energy, temperature, concentration of the solution temperature, concentration of the solution & pH.& pH.pH is a measure of how acidic or basic a pH is a measure of how acidic or basic a solution is. It ranges from 0-14.solution is. It ranges from 0-14.Acid- pH < 7, makes HAcid- pH < 7, makes H+ + ions in water, sourions in water, sourBase- pH > 7, makes OHBase- pH > 7, makes OH-- ions, bitter, ions, bitter, corrosive.corrosive.pH = 7 are neutralpH = 7 are neutral

Acids and BasesAcids and Bases

Feedback from pH levels Feedback from pH levels in the blood signals the in the blood signals the brain forcing a person brain forcing a person holding their breath to holding their breath to breathe.breathe.

6.2 Water and Diffusion6.2 Water and Diffusion

Water makes up 70 to Water makes up 70 to 95% of most 95% of most organisms.organisms.

Life processes occur Life processes occur only when molecules only when molecules & ions are free to & ions are free to move & collide with move & collide with each other.each other.

Water and DiffusionWater and Diffusion

Transports materials Transports materials in blood and sapin blood and sap

Water is Water is polarpolar with an with an unequal distribution of unequal distribution of charge.charge.

Attracts ionic Attracts ionic andand polar substances.polar substances.

Also attracts water inAlso attracts water in cohesioncohesion

Water and DiffusionWater and Diffusion

Positive hydrogen Positive hydrogen attracts negative attracts negative oxygen in weak oxygen in weak hydrogen bonds.hydrogen bonds.These hold biomolecules such as proteins together.Plants use capillary action & surface tension to pull water into the roots.

Water CharacteristicsWater Characteristics

Water resists temperature change which helps Water resists temperature change which helps maintain homeostasis.maintain homeostasis.Expands when it freezes becoming less dense Expands when it freezes becoming less dense so that it floats.so that it floats.Its expansion helps form soil.Its expansion helps form soil.

DiffusionDiffusion

The net movement of The net movement of a substance from an a substance from an area of greater area of greater concentration to an concentration to an area of lesser area of lesser concentration.concentration.This random This random movement results movement results from kinetic energy of from kinetic energy of molecules or molecules or Brownian motion.Brownian motion.

DiffusionDiffusion

Three factors affect Three factors affect diffusion: diffusion:

concentrationconcentration– More conc faster difMore conc faster dif

temperature temperature – Higher fasterHigher faster

pressurepressure– Higher fasterHigher faster

DiffusionDiffusion

The result of The result of diffusion is diffusion is eventual eventual dynamic dynamic equilibrium equilibrium when movement when movement continues but continues but concentration concentration remains the remains the same.same.

DiffusionDiffusion

Molecular Workbench diffusion simulationsMolecular Workbench diffusion simulations

Diffusion in Living SystemsDiffusion in Living Systems

Concentration Concentration gradient gradient – the – the difference in difference in concentration of a concentration of a substance across a substance across a spacespaceWith the gradient With the gradient moves higher to lowermoves higher to lowerAgainst- lower to Against- lower to higherhigher

Diffusion in Living SystemsDiffusion in Living Systems

Oxygen diffuses into Oxygen diffuses into the capillaries of the the capillaries of the lungs because it is lungs because it is less concentrated less concentrated there than in the there than in the alveoli (air sacs).alveoli (air sacs).

It moves with the It moves with the concentration concentration gradient.gradient.

6.3 Biomolecules6.3 Biomolecules

C atoms have 4 C atoms have 4 available electrons for available electrons for bonding covalently inbonding covalently in– SingleSingle– DoubleDouble– Triple bondsTriple bonds

– Straight chainsStraight chains– Branched chainsBranched chains– Rings Rings

BiomoleculesBiomolecules

Built by cells bonding Built by cells bonding small molecules small molecules together in chains or together in chains or polymers.polymers.

Proteins Proteins are long are long chains of amino chains of amino acids.acids.


CarbohydratesCarbohydrates

Made of C, H & OMade of C, H & O

This is sucrose.This is sucrose.

Used by cells to Used by cells to provide energy.provide energy.

Ratio C:H:O = 1:2:1Ratio C:H:O = 1:2:1


LipidsLipidsLarge biomolecules of Large biomolecules of C, H & a little OC, H & a little OInsoluble in waterInsoluble in waterFats, oils, wax, Fats, oils, wax, steroids, cholesterolsteroids, cholesterolNonpolarNonpolarUsed as energy Used as energy storage, insulation & storage, insulation & protective coveringsprotective coverings


ProteinsProteins complex complex biomoleculebiomoleculeC, H, O, N & some. SC, H, O, N & some. SAmino acids linked by Amino acids linked by peptide bonds peptide bonds Imp to muscle Imp to muscle contraction, contraction, transporting O, transporting O, immunity, regulation immunity, regulation & chemical RxNs& chemical RxNs


EnzymesEnzymes protein that protein that changes the rate of a changes the rate of a chemical RxNchemical RxN

Catalysts increase Catalysts increase rate of reactionrate of reaction

Digestion of foodDigestion of food

Other metabolic Other metabolic processesprocesses

Lock and keyLock and key

EnzymesEnzymes

Nucleic AcidsNucleic Acids

Organic compound Organic compound necessary for lifenecessary for life

Polymer made of Polymer made of subunit subunit nucleotidesnucleotides

C, H, O, N, P C, H, O, N, P arranged in 3 groupsarranged in 3 groups– Nitrogenous baseNitrogenous base– Simple sugarSimple sugar– Phosphate groupPhosphate group

Nucleic AcidsNucleic Acids

DNA -coded DNA -coded instructions for instructions for building enzymes & building enzymes & structural proteinsstructural proteins

RNA –forms a copy of RNA –forms a copy of DNA to make proteinsDNA to make proteins

c6-the chemistry of life

Documents

mass number atomic number

different atoms

group of atoms

conserved atoms

number of neutronsatoms

nacl br2same number

atomic mass

electrons e