CHEMISTRY REVIEW

Section 2.1 and 2.2

SECTION 2.1 ATOMS, IONS, AND MOLECULES--OBJECTIVES

Living things consist of atoms of different elements

Ions form when atoms gain or lose electrons

Atoms share pairs of electrons in covalent bonds

THE ATOM The is the smallest basic unit of

matterAtoms are teeny tiny

atom

THE ATOM There are three parts of a an atom

Subatomic particle

Charge Location

_________ Positive Nucleus

_________ Neutral Nucleus

_________ Electron Surrounding nucleus

protonneutronelectron

ELEMENTS An is one particular type of

, and it cannot be broken down into a simpler substance by ordinary chemical meansGold AluminumHelium

element

atom

KEY ELEMENTS In biology, there are SIX very important

elements________Hydrogen_________PhosphorusSulfur________

CHOPS

N

carbon

oxygen

nitrogen

HOW ARE ELEMENTS DIFFERENT The number of protons determines the

of an elementCarbon: 6 protonsOxygen: 8 protons

The number of determines the property of an elementCarbon: 6 electrons, 4 on OUTSIDEOxygen: 8 electrons, 6 on OUTSIDE

identity

electrons

LONELY ATOMS Atoms rarely are found alone in nature

They will do ANYTHING to get to electrons on the outsideStealDumpShare

8

COMPOUNDS A compound is a substance made of

atoms of different bonded togetherResult of sharing, stealing, or dumping

electronsAtoms bonded in a specific ratio

elements

CARBON COMPOUNDS Carbon can form many various

__________ to formCarbohydratesProteinsNucleic acidsLipids

bonds

IONIC BOND __________________ are formed through

the electrical force between oppositely charged ionsOpposites attract!

Ex: Salt aka sodium chloride (NaCl)Positive sodium (Na+)Negative chloride (Cl-)

Ionic bonds

IONS Ions are atoms that have gained or lost

one or more . Results in a change in electrical charge

Gain e- becomes ________________Lose e- becomes ________________

electrons

negativepositive

IONS, CONT. Very important to organisms

Hydrogen ions (H+) needed to produce chemical _____________ in cells

Calcium ions (Ca2+) needed for all _____________ movement in your body

Chloride ions (Cl-) needed for many chemical signals in the brain

energy

muscle

COVALENT BOND Not all atoms easily gain or lose their

electrons! Some atoms ___________ their electrons

instead! _____________ Bond: forms when atoms

share a pair of electronsUsually a very strong bondAtoms may have several covalent bonds to

share several electrons

share

Covalent

COVALENT BOND, CONT. Molecule: two or more atoms held

together by bonds Ex: carbon dioxide (CO2)

Carbon atoms needs 4 electrons to fill outer level, oxygen needs two

Carbon shares with 2 oxygen!

covalent

Ionic Bonds

Covalent Bonds

1. What distinguishes one element from another?

2. Describe the formation of an ionic compound.

3. What is the difference between and ionic bond and a covalent bond?

4. How does a molecule differ from an atom?

5. Explain why a hydrogen atom can become either an ion or a part of a molecule.

SECTION 2.2 PROPERTIES OF WATER--OBJECTIVES Life depends on hydrogen bonds in

water.

Many compounds dissolve in water.

Some compounds form acids or bases.

•Organisms’ bodies, (their _____________),

are made up of mostly ____________________

•The water in cells gives the cell _______________

and ___________________ materials within

organisms.

•All of the processes necessary for an

organism’s life take place within the

______________________________ of the cell

CELLS

WATER

STRUCTURE

TRANSPORTS

WATERY ENVIRONMENT

1. ______________________

2. ______________________

3. ______________________

1. HIGH SPECIFIC HEAT

2. COHESION

3. ADHESION

Negative Charge

Positive Charge Positive Charge

•Water is a “______________” molecule

• Form when atoms in a molecule have ____________ pulls on the _____________ they share.

•Opposite charges of polar molecules can interact to form ____________________ bonds.

• An attraction between a slightly _______________ hydrogen atom and a slightly ______________ atom. (Usually _______________________________)

• Hydrogen bonds are part of the structures of _______________ and of ______________

Shared Electrons

POLAR

UNEQUALELECTRONS

HYDROGEN

POSITIVENEGATIVE

OXYGEN OR NITROGEN

PROTEINSDNA

• Hydrogen bonds give water an abnormally ____________________________.

• Water __________________ changes in temperature because it must _____________ more ____________________ to increase in temperature.

HIGH SPECIFIC HEAT

RESISTS

Absorb heat energy

Cohesion: the attraction among __________________ of the same substance.

Cohesion from hydrogen bonds makes water molecules _____________________.

Cohesion produces __________________, ( “skin on water” )

MOLECULES

STICK TOGETHER

SURFACE TENSION

Adhesion: the attraction among __________________ of ______________ substances.

For example, water molecules stick to other things.

Water in a test tube, (water is attracted

to the ____________)

MOLECULES DIFFERENT

GLASS

Materials such as ________________ and ____________ cannot be transported form one part of an organism to another unless they are dissolved in blood, plant sap, or other water based fluids.

______________: Mixture of a substance that is the same throughout.

___________: Substance that is present in the greater amount and dissolves another substance.

___________: Substance that dissolves in a solvent.

SUGARS

OXYGEN

SOLUTION

SOLVENT

SOLUTE

Some compounds form ______________ or _____________

because they _______________ into _______________

when they dissolve in ___________.

BASE: Compounds that

remove H+ ions

from

a solution

ACID: Compoundsthat releasea proton - a hydrogen ion(H+) – when it dissolves in water

ACIDS BASES

BREAK UP IONS

WATER

Your text here

More acidic More basic

neutral

1. How do polar molecules form hydrogen bonds?

2. What determines whether a compound will dissolve in water?

3. Make a chart that compares acids and bases.

4. How do polar molecules differ from non-polar molecules? How does this difference affect their interactions?

5. Describe an example of cohesion or adhesion that you might observe during your daily life.

HOW DO WE GET TO

“MACRO” IN MACROMOLECU

LES?A detailed look at the process of

polymerization

POLYMERIZATION Building large molecules (_________) from

smaller ones (__________)

• Several step process

polymersmonomers

STEP 1: GET TWO MONOMERS

Both are _____________glucose

STEP 2: BRING THEM _____together

STEP 3: ADD AN ENZYME

enzyme

STEP 3 This __________ carries out a reaction between

the two monomersenzyme

Dehydration synthesis• ___________ ___________: Joins two molecules together by REMOVING _______AKA: condensation reactionwater

STEP 4: BYE WATER!

________H2O

STEP 5: A DIMER!

REMEMBER, DIMER MEANS ________!two

STEP 6: LATHER, RINSE, REPEAT The enzyme can carry out numerous

dehydration synthesis reactions until a macro ___________ is createdEX: ______________

Each one of these monomers is

___________

molecule

starch

glucose

IS THIS REVERSIBLE?

You better believe it!

REVERSING POLYMERIZATION Process called ____________.hydrolysis

• “ __________” means water• “ __________” means to split or

loosen

• This enzyme works by _________ water to a polymer

General process name: depolymerizationturning polymers back into monomers

hydrolysis

adding

BRING IN THE WATER!

ENZYMEH2O

AND THEY ARE SPLIT APART!

What was previous a dimer is now two ______________ againmonomers

OBJECTIVES

Carbon atoms have unique bonding properties.

Four main types of carbon-based molecules are found in living things.

____________________

____________________

____________________

____________________

____________________

PROTEIN

LIPIDS

CARBOHYDRATES

ATP

NUCLEIC ACID

MONOMER & POLYMER

Each subunit of a complete carbon-based molecule is called a ______________

A _____________ is a large molecule, or macromolecule, made of many monomers bonded togetherMonomers of a polymer may be

the same (ex. Starches)Or different (proteins)

monomer

polymer

COMPOUND BUILDING BLOCK

(POLYMER) (MONOMER)

PROTEIN AMINO ACID

LIPID (FAT) FATTY ACID

CARBOHYDRATE SUGARS

NUCLEIC ACIDS NUCLEOTIDE

CARBOHYDRATES

Carbohydrates are molecules composed of carbon, ______________, and oxygen Include sugars & starchesCan be broken down to provide useable

energy for cellsMajor part of plant cell structure

The most basic carbs are simple sugars, _______________________

Polysaccharides are ______________ of monosaccharides

hydrogen

monosaccharides

polymers

•USED BY CELLS FOR __________ ___________ AND __________ ____________.

SIMPLE CARBS = _______________________________ COMPLEX CARBS = _____________________________ _____________________________

ENERGY SOURCEENERGY STORAGE

ONE OR TWO SUGAR MOLECULES

LONG CHAINS OF SUGAR MOLECULES

Ex) Starches such as potato,

pasta, bread________________________________

________________________________

PROTEINS

Proteins are the most varied of the carbon-based molecules in organismsHave a role in movement, eyesight,

digestion,etc A protein is a polymer made of

monomers called amino acids _________________ are molecules that

contain carbon, hydrogen, oxygen, nitrogen, and sometimes sulfurOrganisms use 20 different amino acids to

build proteinsThe body makes 12 of the 20, the other 8

come from food

Amino acids

•MAKE UP _________________.

•INVOLVED IN ALL _______ ____________.

•BUILDING BLOCKS = _________ __________.

•_________________= TYPE OF PROTEIN THAT STARTS AND SPEEDS UP CHEMICAL REACTIONS IN CELLS.

CELLS

LIFE PROCESSES

AMINO ACIDS

ENZYME

LIPIDS Lipids are nonpolar molecules that

include fats, oils, and cholesterolContain chains of carbon bonded to oxygen

& hydrogenSome broken down for useable energyOthers are part of a cell’s structure

________________ are chains of carbon atoms bonded to hydrogen atoms.Saturated fatty acids have single carbon-

carbon bonds Unsaturated fatty acids have double

carbon-carbon bonds

Fatty acids

•DON’T MIX WITH ______________.

•PHOSPHOLIPIDS – MAKE UP ________ ______________.

•FATS AND OILS THAT _________ ___________.

•ORGANISMS USE FATS AND OILS WHEN THEY HAVE USED UP ___________________.

•_________- SOLID AT ROOM TEMPERATURE.

•_________- LIQUID AT ROOM TEMPERATURE.

WATER

CELL MEMBRANE

STORE ENERGY

CARBOHYDRATES

FATS

OILS

•MAJOR ___________ ___________ MOLECULE IN CELL.

•ENERGY IN __________________ AND __________ AND _____________________ MUST BE TRANSFERRED TO ATP IN CELL TO BE USED.

ENERGY CARRYING

CARBOHYDRATES LIPIDS PROTEINS

NUCLEIC ACIDS Detailed instructions to build proteins

are stored in extremely long carbon-based molecules called nucleic acids____________________ are polymers that are

made up of monomers called nucleotides

Nucleic acids differ from the other carbon-based moleculesThe others have a large # of functionsNucleic acids have just 1 function… make

proteins DNA stores info for putting amino acids together

to make proteins RNA helps to build proteins

Nucleic acids

•HAVE ALL INFO NEEDED TO MAKE __________.

•“_______________” OF LIFE.

•BUILDING BLOCKS OF _____________.

•TWO TYPES: ________ AND _______.

PROTEIN

BLUE PRINT

NUCLEOTIDES

DNA RNA

1. What is the relationship between a polymer and a monomer?

2. Explain how both nucleic acids and proteins are polymers. Be sure to describe the monomers that make up the polymers.

3. How are carbohydrates and lipids similar? How are they different?

4. Explain how the bonding properties of carbon atoms result in the large variety of carbon-based molecules in living things?

2.4Chemical Reactions

OBJECTIVES

Bonds break and form during chemical reactions.

Chemical reactions release or absorb energy.

Chemical Reaction... Gummy bear torture

CHEMICAL REACTIONS

CHEMICAL REACTIONS

Bonds & during chemical reactionsPlant/Animal cells break down sugars to get

usable energyCells build protein molecules by bonding

amino acids together

Chemical reactions change substances into different substances by breaking and forming chemical bonds

break form

CHEMICAL REACTIONS are the substance changed

during a chemical reactionsOxygen (O2) & Glucose (C6H12O6)

are the substances made by a chemical reactionCarbon Dioxide (CO2) & Water (H2O)

6O2 + C6H12O6 6CO2 + 6H2O

Reactants Products

Reactants

Products

IT’S ALL ABOUT THE ENERGY Energy is __________ to break bonds in

molecules is the amount of energy that will

break a bond between two atoms.Every atom has different bond energy

A SPECIFIC amount of energy is needed to break bonds in an oxygen molecule

A SPECIFIC amount of energy is needed to break bonds in a glucose molecule

Energy is ___________ when bonds are formedThe amount of energy released is equal to the

energy that breaks the same bond Energy needed to break apart water molecule = energy

released when hydrogen & oxygen atoms bond to form a water molecule

Bond energy

needed

released

CHEMICAL EQUILIBRIUM Many reactions are _________________!

The move in both directions at the same time! However many RXNs go from reactants to

products until the reactants are all used up

Tend to go in one direction depending on the concentrations of the reactants and products They try to balance each other!

When a RXN takes place @ equal rate in both directions, the reactant & product concentrations stay the same This is called _________________ Equilibrium is reached when both the

reactants and products are made at the same rate

reversible

equilibrium

CHEMICAL REACTIONS

All chemical reactions involve changes in Energy added to the reactants breaks their

chemical bondsWhen new bonds form in the products, energy is

released

Energy is both and during a chemical reaction!Some release more energy than they absorb

(Generous)Some absorb more energy than they release

(Greedy)

energy

absorbed released

CHEMICAL REACTIONS, CONT. Generous chemical RXNs that release more energy than they absorb= reactionExcess energy is the difference in bond

energy between the reactants and productsExcess energy is often released as heat or

light Cellular respiration releases usable energy for

your cells & heat!

Exothermic

CHEMICAL REACTIONS, CONT.

Greedy chemical RXNs that absorb more energy than they release= reaction

In photosynthesis, plants absorb energy from sunlight and use that to make sugars and carbohydrates

Endothermic

BUT HOW DOES A RXN START?

Some energy must first be absorbed by the reactants in ANY chemical reactionThe amount of energy needed will vary

is the amount of energy that needs to be absorbed for a chemical reaction to startPush a rock up a hill

Activation energy

1. Hydrogen peroxide (H2O2) breaks down into water (H2O) and oxygen (O2). Explain why this is a chemical reaction. What are the reactants and the products in the reaction?

2. How do endothermic and exothermic reactions differ?

3. What must be true about the bond energies of the reactants and the products of the exothermic process below. Explain.

6O2 + C6H12O6 6CO2 + 6H2O

4. Why might it not always be possible to determine the reactants and the products in a reaction? Explain your answer in terms of chemical equilibrium.

2.5Enzymes

OBJECTIVES

A catalyst lowers activation energy.

Enzymes allow chemical reactions to occur under tightly controlled conditions.

CATALYST To start a chemical RXN, activation energy

is necessary The reaction may happen very slowly Reactants may not interact enough, may not be

high enough concentration

Activation energy & rate of a chemical reaction can be changed by a chemical catalyst A catalyst is a substance that _______________

the activation energy needed to start a reaction Also increases the ________ of the reaction

decreases

rate

ENZYME

_____________ are catalysts for reactions in living thingsLower the activation energy Increase the rate of the reactionDo not effect chemical equilibrium

Does not change the direction of the reaction

Almost all enzymes are Depend on their structure to function

correctlyConditions such as temperature and pH can

affect the function

Enzymes

proteins

SUBSTRATES

An enzyme’s structure is vital because their shape allows only certain reactants to bind to the enzymeThe specific reactants that an enzyme acts

on are called substrates

Substrates bind to enzymes at specific places called Substrates exactly fit the active sites of

enzymes, like a key exactly fits a lockThis is why if an enzyme’s structure

changes, it may not work

active sites

1. How does a catalyst affect the activation energy of a chemical reaction?

2. Describe how the interaction between an enzyme and its substrates changes a chemical reaction.

3. Some organisms live in very hot or very cold acidic environments. Would their enzymes function in a person’s cells? Why or why not?

4. Suppose that the amino acids that make up an enzyme’s active site are changed. How might this change affect the enzyme?