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CHEMISTRY REVIEW
Section 2.1 and 2.2
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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
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THE ATOM The is the smallest basic unit of
matterAtoms are teeny tiny
atom
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THE ATOM There are three parts of a an atom
Subatomic particle
Charge Location
_________ Positive Nucleus
_________ Neutral Nucleus
_________ Electron Surrounding nucleus
protonneutronelectron
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ELEMENTS An is one particular type of
, and it cannot be broken down into a simpler substance by ordinary chemical meansGold AluminumHelium
element
atom
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KEY ELEMENTS In biology, there are SIX very important
elements________Hydrogen_________PhosphorusSulfur________
CHOPS
N
carbon
oxygen
nitrogen
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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
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LONELY ATOMS Atoms rarely are found alone in nature
They will do ANYTHING to get to electrons on the outsideStealDumpShare
8
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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
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CARBON COMPOUNDS Carbon can form many various
__________ to formCarbohydratesProteinsNucleic acidsLipids
bonds
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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
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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
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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
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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
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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
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Ionic Bonds
Covalent Bonds
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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.
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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.
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•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
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1. ______________________
2. ______________________
3. ______________________
1. HIGH SPECIFIC HEAT
2. COHESION
3. ADHESION
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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
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• 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
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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
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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
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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
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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
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Your text here
More acidic More basic
neutral
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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.
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HOW DO WE GET TO
“MACRO” IN MACROMOLECU
LES?A detailed look at the process of
polymerization
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POLYMERIZATION Building large molecules (_________) from
smaller ones (__________)
• Several step process
polymersmonomers
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STEP 1: GET TWO MONOMERS
Both are _____________glucose
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STEP 2: BRING THEM _____together
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STEP 3: ADD AN ENZYME
enzyme
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STEP 3 This __________ carries out a reaction between
the two monomersenzyme
Dehydration synthesis• ___________ ___________: Joins two molecules together by REMOVING _______AKA: condensation reactionwater
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STEP 4: BYE WATER!
________H2O
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STEP 5: A DIMER!
REMEMBER, DIMER MEANS ________!two
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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
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IS THIS REVERSIBLE?
You better believe it!
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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
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BRING IN THE WATER!
ENZYMEH2O
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AND THEY ARE SPLIT APART!
What was previous a dimer is now two ______________ againmonomers
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OBJECTIVES
Carbon atoms have unique bonding properties.
Four main types of carbon-based molecules are found in living things.
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____________________
____________________
____________________
____________________
____________________
PROTEIN
LIPIDS
CARBOHYDRATES
ATP
NUCLEIC ACID
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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
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COMPOUND BUILDING BLOCK
(POLYMER) (MONOMER)
PROTEIN AMINO ACID
LIPID (FAT) FATTY ACID
CARBOHYDRATE SUGARS
NUCLEIC ACIDS NUCLEOTIDE
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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
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•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________________________________
________________________________
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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
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•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
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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
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•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
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•MAJOR ___________ ___________ MOLECULE IN CELL.
•ENERGY IN __________________ AND __________ AND _____________________ MUST BE TRANSFERRED TO ATP IN CELL TO BE USED.
ENERGY CARRYING
CARBOHYDRATES LIPIDS PROTEINS
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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
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•HAVE ALL INFO NEEDED TO MAKE __________.
•“_______________” OF LIFE.
•BUILDING BLOCKS OF _____________.
•TWO TYPES: ________ AND _______.
PROTEIN
BLUE PRINT
NUCLEOTIDES
DNA RNA
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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?
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2.4Chemical Reactions
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OBJECTIVES
Bonds break and form during chemical reactions.
Chemical reactions release or absorb energy.
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Chemical Reaction... Gummy bear torture
CHEMICAL REACTIONS
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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
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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
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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
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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
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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
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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
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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
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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
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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.
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2.5Enzymes
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OBJECTIVES
A catalyst lowers activation energy.
Enzymes allow chemical reactions to occur under tightly controlled conditions.
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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
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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
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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
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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?