Transcript Chemistry Review

ATOM
___________________is
the smallest
basic unit of matter
 Atoms cannot be seen without an
ELECTRON MICROSCOPE
____________________________
 The

It would take more than a trillion years to count
all the atoms in a grain of sand!!!
 There
3
are ______________parts
to an atom:
Subatomic
particle
Charge
Location
proton
_________
Positive
Nucleus
neutron
_________
electron
_________
Neutral
Nucleus
Electron
Surrounding
nucleus
ELEMENT
___________________is
one particular
type of _______________,
and it cannot be
ATOM
broken down into a simpler substance by
ordinary chemical means.
 An



Gold
Aluminum
Helium
ALL ORGANISMS
__________________,
there are SIX very
important elements:
 In
______________________
 nitrogen
______________________
 carbon
______________________
 hydrogen
______________________
 oxygen
______________________
 phosphorous
______________________
 sulfur
LEARN THEM USING THIS MNEMONIC
 The
number of protons determine the
_______________
of an element – this #
IDENTITY
NEVER changes!!!


Carbon: 6 protons
Oxygen: 8 protons
PROTONS
number of _______________determine
the chemical properties of an element – this
# CAN change!!!
 The


4
Carbon: 6 electrons, _____on
OUTSIDE
Oxygen: 8 electrons, _____
6 on OUTSIDE
 The
number of neutrons can also change
# of protons (p),
also number of
electrons (e-)
REALLY IMPORTANT – ALL ELEMENTS
ARE ELECTRICALLY NEUTRAL –
WHY???
Mass of
element; # of
protons and
neutrons (n)
 Using
your table, find:
 Atomic
number of H ______
 Atomic mass of S______
 Number of electrons in N_______
 Atomic number of Calcium_______
 Number of protons in element #8_______
 Atoms
are not found alone in nature because
they are not chemically stable
 What does this mean?
 Energy levels and “happiness”
8 e-s
8 e-s
N
Nucleus
2 e-s
A
compound is a substance made of atoms of
different ELEMENTS bonded together




Result from either sharing or transferring
electrons to become stable
The atoms in a compound are bonded in a
specific ratio
The characteristics of the compound are VERY
different than the properties of the elements
that make them up – NaCl
http://www.bing.com/videos/search?q=ionic+and+cov
alent+bonds&qs=n&form=QBVR&pq=ionic+and+cova
lent+bonds&sc=8-24&sp=1&sk=#view=detail&mid=FC661AB5D4927AD1FDD7F
C661AB5D4927AD1FDD7
 https://www.youtube.com/watch?v=_M9khs8
7xQ8
 IONIC
BONDS are formed through the
electrical force between oppositely charged
ions

Opposites attract!
 Ex:


Salt aka sodium chloride (NaCl)
Positive sodium (Na+)
Negative chloride (Cl-)
 Ions
are atoms that have gained or lost one
or more ELECTRONS.
 Remember, atoms do this to have stable
outer energy levels.
 Results in a change in electrical charge


Gain eLose e-
 “PLANG”
becomes NEGATIVE
becomes POSITIVE
 Not
all atoms easily gain or lose their
electrons!
 Some atoms SHARE their electrons instead!
 COVALENT Bond: forms when atoms share a
pair of electrons


Usually a very strong bond
Atoms may have several covalent bonds to share
several electrons
 Molecule:
two or more atoms held together
by COVALENT bonds
 Ex: carbon dioxide (CO2)


Carbon atoms needs 4 electrons to fill outer
level, oxygen needs two
Carbon shares with 2 oxygen!
 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
1. ______________________
2. ______________________
3. ______________________
Negative Charge
•Water is a “______________” molecule
•Form when atoms in a molecule
have ____________ pulls on the
_____________ they share.
Positive Charge
•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 ______________
Positive Charge
Shared Electrons
• Hydrogen bonds give water an abnormally ____________________________.
•Water __________________ changes in temperature because it must
_____________ more ____________________ to increase in temperature.
Cohesion: the attraction among
__________________ of the same
substance.
Cohesion from hydrogen bonds makes
water molecules _____________________.
Cohesion produces __________________,
( “skin on water” )
Adhesion: the attraction among
__________________ of ______________
substances.
For example, water molecules stick to other
things.
Water in a test tube, (water is attracted
to the ____________)
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.
Some compounds form ______________ or _____________
because they _______________ into _______________
when they dissolve in ___________.
BASE:
ACID:
Compounds
that release
a proton
- a hydrogen ion(H+) –
when it dissolves
in water
Compounds that
remove H+ ions
from
a solution
1. How do polar molecules form hydrogen bonds?
2. What determines whether a compound will dissolve in water?
3. Compare 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.
 Carbon
can form many various ___________
to form




Carbohydrates
Proteins
Nucleic acids
Lipids
 Building
large molecules (_________) from smaller
ones (__________)
• Several step process
Both are _____________
 This
__________ carries out a reaction between the
two monomers
• ___________ ___________: Joins two
molecules together by REMOVING
_______
AKA: condensation reaction
H2O
________
REMEMBER, DIMER MEANS ________!
 The
enzyme can carry out numerous dehydration
synthesis reactions until a macro ___________ is
created

EX: ______________
Each one of
these
monomers is
___________
You better believe it!
 Process
called ____________.
• “ __________” means water
• “ __________” means to split or loosen
• This enzyme works by _________ water
to a polymer
General process name: depolymerization
turning polymers back into monomers
ENZYME
H2O
What was previous a dimer is now two ______________ again
____________________
____________________
____________________
____________________
____________________
 Each
subunit of a complete carbonbased molecule is called a
A
is a large molecule, or
macromolecule, made of many
monomers bonded together


Monomers of a polymer may be the
same (ex. Starches)
Or different (proteins)
COMPOUND
BUILDING BLOCK
(POLYMER)
(MONOMER)
PROTEIN
AMINO ACID
LIPID (FAT)
FATTY ACID
CARBOHYDRATE
SUGARS
NUCLEIC ACIDS
NUCLEOTIDE
 Carbohydrates
carbon,



are molecules composed of
, and oxygen
Include sugars & starches
Can be broken down to provide useable energy
for cells
Major part of plant cell structure
 The
most basic carbs are simple sugars,
 Polysaccharides
are
monosaccharides
of
 Proteins
are the most varied of the carbonbased molecules in organisms

Have 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 sulfur


Organisms use 20 different amino acids to build
proteins
The body makes 12 of the 20, the other 8 come
from food
 Lipids
are nonpolar molecules that include
fats, oils, and cholesterol



Contain chains of carbon bonded to oxygen &
hydrogen
Energy storage
Phospholipids make up _____________________
 ________________
are chains of carbon
atoms bonded to hydrogen atoms.


Saturated fatty acids have single carbon-carbon
bonds (solid @ room temp)
Unsaturated fatty acids have double carboncarbon bonds (liquid @ room temp)
•MAJOR ___________ ___________ MOLECULE IN CELL.
•ENERGY IN __________________ AND __________ AND
_____________________ MUST BE TRANSFERRED TO
ATP IN CELL TO BE USED.
 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
•HAVE ALL INFO NEEDED TO MAKE __________.
•“_______________” OF LIFE.
•BUILDING BLOCKS OF _____________.
•TWO TYPES: ________ AND _______.
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?
 Bonds
&
during chemical
reactions


Plant/Animal cells break down sugars to get
usable energy
Cells build protein molecules by bonding amino
acids together
 Chemical
reactions change substances into
different substances by breaking and forming
chemical bonds

are the substance changed during a
chemical reactions


Oxygen (O2) & Glucose (C6H12O6)
are the substances made by a
chemical reaction

Carbon Dioxide (CO2) & Water (H2O)
6O2 + C6H12O6
6CO2 + 6H2O
 Energy
needed to break bonds in molecules
is __________
released
 Energy is ___________
when bonds are formed
 Generous
chemical RXNs that release more
energy than they absorb



=
reaction
Excess energy is the difference in bond energy
between the reactants and products
Excess energy is often released as heat or light

Cellular respiration releases usable energy for your
cells & heat!
 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
 Some
energy must first be absorbed by the
reactants in ANY chemical reaction


The amount of energy needed will vary
is the amount of energy
that needs to be absorbed for a chemical
reaction to start

Push a rock up a hill
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 does energy related to the formation and breaking of bonds?
3. How do endothermic and exothermic reactions differ?
 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
 _____________
are catalysts for reactions
in living things



Lower the activation energy
Increase the rate of the reaction
Do not effect chemical equilibrium

Does not change the direction of the reaction
 Almost


all enzymes are
Depend on their structure to function correctly
Conditions such as temperature and pH can
affect the function
 An
enzyme’s structure is vital because their
shape allows only certain reactants to bind
to the enzyme

The specific reactants that an enzyme acts on
are called substrates
 Substrates
called


bind to enzymes at specific places
Substrates exactly fit the active sites of
enzymes, like a key exactly fits a lock
This is why if an enzyme’s structure changes, it
may not work
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?