chapter 2 the chemistry of life. what we are learning today section 1: the nature of matter rreview...

Chapter 2Chapter 2

The Chemistry of LifeThe Chemistry of Life

What We are Learning Today

Section 1: The Nature of MatterReview atoms and element structure

Identify the different ways chemicals bond

Define Key Terms

Atoms• The smallestsmallest unit of matter that cannot cannot

be broken down by chemical meansbe broken down by chemical means

– Very small and always changingalways changing

• 3 particles make up an atom– Electrons (-) – Protons (+)– Neutrons (neutral)

Attract each other…

*Therefore atom itself has no charge (negative electron cancels out positive proton)

Atomic Structure• Electron

Cloud made of electrons, which have (-) charge so Electron Cloud = (-)

• Nucleus made up of protons and neutrons, protons have (+) charge and neutrons have neutral (no) charge so nucleus has a (+) charge

Elements• An element is a pure substancepure substance

made of only one kind of atom– Represented by chemical symbolsRepresented by chemical symbols

(C, N, H)(C, N, H)– Elements differ in the # of protonsElements differ in the # of protons

(C=6, O=8)(C=6, O=8)• Equal to the Equal to the atomic numberatomic number

– Number of protons usually = number Number of protons usually = number neutronsneutrons• Are exceptions…Are exceptions…

Differences in Differences in ElementsElements

• Atomic Number all atoms of a particular element have the same number of protons which is called the atomic number.– Ex: Helium = 2 b/c it has 2 protons

Chemical Bonding• Atoms can Atoms can join togetherjoin together to form a to form a stablestable

substancesubstance– The The forceforce that joins atoms together is called a that joins atoms together is called a

chemical bondchemical bond

• A A compoundcompound is a is a mixturemixture of the atoms of 2+ of the atoms of 2+ different elements joined together in a different elements joined together in a chemical bondchemical bond

•3 Types3 Types– CovalentCovalent– HydrogenHydrogen– IonicIonic

Covalent bond• When 2+ atoms When 2+ atoms share electronsshare electrons to to

form a molecule.form a molecule.• Arrangement of electrons determine Arrangement of electrons determine

how atoms bond togetherhow atoms bond together– Electron levelsElectron levels

•Closest to nucleusClosest to nucleus = 2 electrons = 2 electrons•Second levelSecond level = 8 electrons… = 8 electrons…

– Atom becomes Atom becomes stablestable when the when the outer electron outer electron level is fulllevel is full

– If it is not full it will react with atoms that can If it is not full it will react with atoms that can provide the electrons needed.provide the electrons needed.

Energy LevelsEnergy LevelsCarbon Energy Levels

Carbon = 6 electrons

Atomic # = number of protons = # electrons1

2

5

3

4

6

A Water Molecule has a A Water Molecule has a POLARPOLAR Covalent BondCovalent Bond• Water is made Water is made

of Hydrogen of Hydrogen and Oxygenand Oxygen

• Hydrogen =HHydrogen =H – 1 electron in its 1 electron in its

outer most outer most levellevel

• Oxygen =OOxygen =O – 6 electrons in 6 electrons in

its outer most its outer most levellevelThey react to They react to fill each ones fill each ones outer most outer most

levellevel

22

1

65

4

32

Hydrogen Hydrogen bondsbonds

• Electrons in a water molecule are shared by oxygen and hydrogen atoms– Electrons more Electrons more

strongly attracted to strongly attracted to the oxygen nucleus the oxygen nucleus than by the hydrogen’sthan by the hydrogen’s

– This unequal distribution This unequal distribution of electrical charge are of electrical charge are

called called polar polar moleculesmolecules

Polar Molecule(Water)

Which pole attracts which pole?

Ionic BondingIonic Bonding• Sometimes atoms or molecules

gain or loose and electron– “Ion”– Electric charge b/c they contain an

unequal number of electrons and protons

Gaining/Losing an Electron

• GainingGaining Makes the atom more Makes the atom more negativenegative– Adds a (-) charge onto the atom… Adds a (-) charge onto the atom…

electrons are (-)electrons are (-)

• LosingLosing Makes the atom more Makes the atom more positivepositive– Adds a (+) charge onto the atom… Adds a (+) charge onto the atom…

negative charges were lostnegative charges were lost

Ionic Bond Example Na LOST Na LOST an e- so an e- so it it became became more more positivepositive

Cl Cl GAINED GAINED an e- so an e- so it it became became more more negativnegativee

Closure• Do you remember anything about

atoms?– Make an atom of carbon Make an atom of carbon using playdoughusing playdough

– Include the # •protons, •neutrons •and electronselectrons!

CarbonCarbon

66

What did we learn today?• Word Association

– Come to the board and write down any word you remember from today’s lesson!

QUIZ

• FRIDAY – quiz on Chapter 2 section 1 & 2– Period 12 Quiz THURSDAY

Exit Ticket

• Draw a carbon atom (Atomic number = 6)– Label all the parts and correctly show the

number of electrons in the right levels

• Write 3 things you learned today

• Begin 2.1 Section Review– Page 30– Questions 1-4– Finish for HW

Chapter 2Section 2: Water & Solutions

• Water in Living Things– Storage of heat– Cohesion/ adhesion

• Aqueous Solutions– Polarity– Acids and Bases

Chapter Chapter 22

Section 2Section 2

Water and SolutionsWater and Solutions

NotesNotes

Water in Living Water in Living ThingsThings

• 70%70% of your body is made of water of your body is made of water• Water helps Water helps move nutrientsmove nutrients into into

and out of your cellsand out of your cells

• Certain properties of water make it Certain properties of water make it such an important substance for lifesuch an important substance for life– Storage of heatStorage of heat– Cohesion & AdhesionCohesion & Adhesion

Storage of HeatStorage of Heat• WaterWater heats more slowly and heats more slowly and

retains heatretains heat longer than many longer than many other substancesother substances

• Many organisms release heat Many organisms release heat through water through water evaporationevaporation– SweatingSweating

• Helps maintain Helps maintain homeostasishomeostasis

Cohesion Cohesion & & AdhesionAdhesion• CohesionCohesion

– Attraction Attraction betweenbetween substances of the substances of the samesame kind kind

– Surface tensionSurface tension prevents water from breaking easily prevents water from breaking easily– The The hydrogen bondshydrogen bonds betweenbetween water molecules cause water molecules cause

the the cohesion of liquid watercohesion of liquid water

• AdhesionAdhesion– Attraction Attraction betweenbetween substances of a substances of a

differentdifferent kind kind• Substances get wetSubstances get wet• Capillary actionCapillary action water molecules move up water molecules move up

through a narrow tube (stem of plant)through a narrow tube (stem of plant)

• Because of these water can move up the Because of these water can move up the stems of leavesstems of leaves

Aqueous SolutionsAqueous Solutions

• Many substances dissolve in waterMany substances dissolve in water• Solution: Solution: a mixture in which one or more a mixture in which one or more

substances are evenly distributed in another substancesubstances are evenly distributed in another substance

– Salt waterSalt water– GatoradeGatorade

• Because certain substances can Because certain substances can dissolve in water they can more dissolve in water they can more easily move throughout the bodyeasily move throughout the body

PolarityPolarity• Enables many substances to dissolve in waterEnables many substances to dissolve in water

– When ionic compounds are dissolved in water, When ionic compounds are dissolved in water, • ions become surrounded by polar water moleculesions become surrounded by polar water molecules

• Ions and molecules become Ions and molecules become evenly distributed in the evenly distributed in the waterwater

• Non polar molecules do not dissolve in Non polar molecules do not dissolve in water well (oils)water well (oils)

Acids and BasesAcids and Bases

• Pure waterPure water always has a always has a low low concentrationconcentration of hydrogen ions (H+) and of hydrogen ions (H+) and hydroxide ions (OH-)hydroxide ions (OH-)– Compounds that Compounds that form hydrogen ionsform hydrogen ions when when

dissolved in water are dissolved in water are acidsacids– Compounds that Compounds that reducereduce the concentration of the concentration of

hydrogen ions in water are called hydrogen ions in water are called basesbases• lower the concentration of hydrogen ions because lower the concentration of hydrogen ions because

hydroxide ions react with hydrogen ions to form waterhydroxide ions react with hydrogen ions to form water

(H+) + (OH-) (H+) + (OH-) WATER WATER

pH ScalepH Scale

SECTION REVIEW QUESTIONSSECTION REVIEW QUESTIONS

• Chapter 2.2 Section Review Chapter 2.2 Section Review Questions!Questions!

On your note sheets…On your note sheets…

• Write at least 1 example of a– Carbohydrate– Lipid (fats)– Protein– Nucleic acid

– What do you think they all have in common?

Question #1

Which of the following is NOT an organic molecule?

CarbohydrateIceLipidNucleic Acid

Question #2

Write down 3 types of carbohydrates AND give examples of each (how many sugars in each)

Monosaccharide- 1 sugarDisaccharide – 2 sugarPolysaccharide- 3 sugar (starch, cellulose,

glycogen)

Index Card #3

• Are lipids polar or non polar?– Non polar

• Do they dissolve in water?– no

• Give 3 examples of Lipids– Steroids, fats, waxes

Card#4

• What are the building blocks of proteins?– Amino Acids

• Give 2 examples of proteins and where they are located in the body.– Keratin- hair– Hemoglobin- blood

Card 5

What is a fatty acid and which bio-molecule does it belong to?

it is a lipid attached to a glycerol backbone

It is a lipid

Card 6

Give 2 examples of carbohydrates produced by plants

starch, cellulose

Give 1 example of carbohydrates produced by animals.

glycogen

Card 7

• What are three characteristics of saturated fats? – Solid at room temp– Made from animal fats– Straight chain

Card 8

What are 3 characteristics of unsaturated fats

liquids at room temperature

from plants

structure is kinked because of the

double carbon bond

Card 9

• What are 2 examples of nucleic acids?– DNA and RNA

10

• What is the function of nucleic acids?

11

• What is the function of lipids?

12

• Which type of fat has a kink in the structure?

13

• All organic compounds contain what element?

2.3 Chemistry of Cells2.3 Chemistry of Cells

• Most matter in your body that isn’t water ISIS an organic molecule

– Organic = Carbon based• 4 classes of organic molecules in your

body (can’t function w/o them)

– Carbohydrates– Lipids– Proteins– Nucleic Acids

StructureStructureWhere its foundWhere its found

ExamplesExamplesFunctionFunction

OtherOther

Carbohydrates

• Organic molecules made of carbon, hydrogen and Organic molecules made of carbon, hydrogen and oxygenoxygen

• Major source of energy for the bodyMajor source of energy for the body

• Found in most foods (fruits, veggies, grain) in the Found in most foods (fruits, veggies, grain) in the form of sugarsform of sugars– 3 types of sugars

• Monosaccharide (simple sugars; glucose & fructose)Monosaccharide (simple sugars; glucose & fructose)

• Disaccharide (double sugars; sucrose)Disaccharide (double sugars; sucrose)

• Polysaccharide (3+monosaccharides; starch, glycogen)Polysaccharide (3+monosaccharides; starch, glycogen)



OtherOther

Examples of Sugars (Carbs)• PolysaccharidesPolysaccharides

storehouses for energystorehouses for energy

• starch, glycogen, cellulosestarch, glycogen, cellulose

– Starch – made by plantsStarch – made by plants

– Glycogen- made by Glycogen- made by animalsanimals• Both made from linked Both made from linked

glucose molecules (pg 34)glucose molecules (pg 34)

– Cellulose- made by Cellulose- made by plants (for structure)plants (for structure)



OtherOther

LipidsLipids• Non-polar molecules… Non-polar molecules… soluble or non-soluble?soluble or non-soluble?

• Fats, phospholipids, steroids and waxesFats, phospholipids, steroids and waxes• Steroids Steroids (cholesterol, estrogen, testosterone)(cholesterol, estrogen, testosterone)

• Important for structure and function of Important for structure and function of cell membranescell membranes– Found in animal cell membranes & pigmentsFound in animal cell membranes & pigments

• Lipids store energyLipids store energyStructureStructure

Where its foundWhere its foundExamplesExamplesFunctionFunction

OtherOther

Write this in OTHER!Write this in OTHER!



OtherOther

Structure of LipidsStructure of Lipids• 3 fatty acids bonded to a glycerol molecule 3 fatty acids bonded to a glycerol molecule

backbone backbone – Fatty acid is long chain of carbon atoms with Fatty acid is long chain of carbon atoms with

hydrogen bonded to themhydrogen bonded to them

• Strong bonds between carbon and hydrogen Strong bonds between carbon and hydrogen can store lots of energy can store lots of energy



OtherOther

Saturated and Saturated and UnsaturatedUnsaturatedSaturated

• All carbons have single bonds to hydrogen

• Most animal fats– Butter, lard, grease

• Usually solids at room temperature

Unsaturated• Some carbons linked by

a double covalent bonddouble covalent bond– Causes kinks in chain

• Plant oils, olive oil, fish oils

• Liquids at room temperature



OtherOther

Unsaturated Fats

Vocabulary!

• Complete Chapter 2.3 Vocabulary! – HW if not finished!

What did we talk about yesterday?

• What is the name of compounds that contain carbon?

• What are the 3 types of carbohydrate “sugars?”

• What organism makes cellulose? • What organism makes glycogen?• Are lipids polar or non-polar?• What are some examples of lipids?• What is the difference between saturated

and unsaturated fats?

ProteinsProteins• Structure: Structure:

– Large molecules formed by linked Large molecules formed by linked smaller molecules called amino acids smaller molecules called amino acids (AA)(AA)

• FunctionFunction::– AA are building blocks of proteinsAA are building blocks of proteins

• Only 20 AAOnly 20 AA

– Cause various shapes of proteinsCause various shapes of proteins– Some proteins are enzymes (help Some proteins are enzymes (help

chemical reactions)chemical reactions)– Others used for structureOthers used for structure

• Skin, ligaments, bone (Collagen)Skin, ligaments, bone (Collagen)• Hair & nails (keratin)Hair & nails (keratin)• Blood (hemoglobin)Blood (hemoglobin)



OtherOther

Nucleic AcidsNucleic Acids• Where FoundWhere Found

– All cells contain nucleic acids All cells contain nucleic acids • StructureStructure

Long chain of smaller molecules Long chain of smaller molecules ( called nucleotides)( called nucleotides)

– 3 parts 3 parts • SugarSugar• BaseBase• Phosphate group (P& O)Phosphate group (P& O)

• Function:Function:– Store genetic infoStore genetic info

• Examples: Examples: – 2 types of nuclei acids2 types of nuclei acids

• DNA- deoxyribonucleic acidDNA- deoxyribonucleic acid• RNA- ribonucleic acidRNA- ribonucleic acid



OtherOther

Chapter 2.4 Chapter 2.4 Energy & Chemical Energy & Chemical

ReactionsReactions• EnergyEnergy– ability to move or change matterability to move or change matter

• Many formsMany forms – light, heat, chemical energy, mechanical light, heat, chemical energy, mechanical

energy, electrical energyenergy, electrical energy

• Can be stored or releasedCan be stored or released – by chemical reactions (build/break bonds)by chemical reactions (build/break bonds)

• MetabolismMetabolism all of the chemical all of the chemical reactions that occur within an organismreactions that occur within an organism

Enzymes and Activation Energy

•Activation energyActivation energy –amount of energy needed to start a reaction

–Can take a long time for reaction to occur•Heat the substance? NO!•Add a catalystcatalyst!! YES

– ENZYMESENZYMES!»Lower the amount of energy needed Lower the amount of energy needed to start the reaction without to start the reaction without changing the original reactantschanging the original reactants

EnzymesEnzymes• Shape specific• EnzymeEnzyme holds the reactant• Fits like puzzle piece

– Active site

• Each enzymeenzyme has its own specific substratesubstrate (reactant)

• pH, Temperature, environment can affect

Section Review Questions

• 2.4 pg42– #1-4 Write the Questions & Answer

• Complete 2.3 Directed Reading Worksheet

• Finish 2.4 Vocabulary Terms

• Complete 2.4 Directed Reading Sheet

chapter 2 the chemistry of life. what we are learning today section 1: the nature of matter rreview...

Documents

atom electrons

electrons atomic

unequal number of electrons

carbon atom atomic number

arrangement of electrons

atom of carbon

protons c

charge negative electron