Transcript PP Chapter 2

Interest Grabber
Section 2-1
What’s the Matter?
All of the materials around you are made up of matter. You are made up of
matter, as are the chair you sit on and the air you breathe.
1. Give an example of solid matter.
2. Give an example of liquid matter.
3. Give an example of gaseous matter.
4. Is all matter visible?
5. Does all matter take up space?
Go to
Section:
Section Outline
Section 2-1
2–1
The Nature of Matter
A. Atoms
B. Elements and Isotopes
1. Isotopes
2. Radioactive Isotopes
C. Chemical Compounds
D. Chemical Bonds
1. Ionic Bonds
2. Covalent Bonds
3. Van der Waals Forces
Go to
Section:
2-1 The Nature of Matter
Atoms
•At Atom is the basic unit of matter.
•There are 3 subatomic particles in an atom.
They are called a proton, neutron and an
electron.
•The Nucleus of an atoms is the center of an
atom and is made up of protons and neutrons.
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Section:
2-1 The Nature of Matter
Atoms
Particle
Charge
Location in
Atom
Proton
Positive
Nucleus
Neutron
Neutral
Nucleus
Electron
Negative
Surrounding
nucleus
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Section:
2-1 The Nature of Matter
Atoms
Protons +
Neutrons 0
electrons -
Atoms have equal numbers of electrons and protons, and these subatomic
particles have equal , but opposite charges
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Section:
An Element in the Periodic Table
Section 2-1
6
Atomic number
Element name
C
Carbon
12.011
Element symbol
Mass number
A chemical element is a pure substance that consists entirely of one type of
atom.
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Section:
2-1 The Nature of Matter
Elements and Isotopes
•An element’s atomic number represents the number of
protons in an atom of the element.
•An element’s mass number represents the number of
protons and neutrons in an atoms of the element.
•Isotopes are atoms of the same element that differ in
the number of neutrons they contain.
•Isotopes are identified by their mass number.
•They have the same chemical properties because they
have the same number of electrons.
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Section:
Figure 2-2 Isotopes of Carbon
Section 2-1
Nonradioactive carbon-12
Nonradioactive carbon-13
6 electrons
6 protons
6 neutrons
6 electrons
6 protons
7 neutrons
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Section:
Radioactive carbon-14
6 electrons
6 protons
8 neutrons
2-1 The Nature of Matter
Elements and Isotopes
•A chemical compound is a substance formed by the
chemical combination of 2 or more elements in definite
proportions.
•H20- 2 Hydrogen to 1 Oxygen
•CO2- 1 Carbon to 2 Oxygen
•NaCl- 1 Sodium to 1 Chlroine
•C6H12O6-6 Carbon to 12 Hydrogen to 6 Oxygen
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Section:
2-1 The Nature of Matter
Chemical Bonds
•Chemical bonds holds atoms in compounds
together.
•The 2 types of chemicals bonds are ionic and
covalent
•Ionic bonds form when one or more electrons
are transferred from one atom to another.
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Section:
Figure 2-3 Ionic Bonding
Section 2-1
Sodium atom (Na)
Chlorine atom (Cl)
Sodium ion (Na+)
Chloride ion (Cl-)
Transfer
of electron
Protons +11
Electrons -11
Charge
0
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Section:
Protons +17
Electrons -17
Charge
0
Protons +11
Electrons -10
Charge
+1
Protons +17
Electrons -18
Charge
-1
Figure 2-3 Ionic Bonding
Section 2-1
Sodium atom (Na)
Chlorine atom (Cl)
Transfer
of electron
Protons +11
Electrons -11
Charge
0
Protons +17
Electrons -17
Charge
0
Sodium ion (Na+)
Protons +11
Electrons -10
Charge
+1
Chloride ion (Cl-)
Protons +17
Electrons -18
Charge
-1
•An ion is an atoms that is positively or negatively charged because it has lost or
gained electrons.
•If it loses an electron it has a positive charge
•If it gains an electron it has a negative charge
Show video 2B
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Section:
2-1 The Nature of Matter
Chemical Bonds
•Covalent bonds form when electrons are shared
between atoms
•A single bond is when atoms share 2 electrons
•A double bond is when atoms share 4 electrons
•A triple bond is when atoms share 6 electrons
•A molecules is the structure that results when atoms
are joined together by covalent bonds
•Van der Waals forces are the slight attractions that
develop between oppositely charged regions of nearby
molecules.
•Show video 2A and 2C
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Section:
Interest Grabber
Section 2-2
Water, Water Everywhere
If you have ever seen a photograph of Earth from space, you know that
much of the planet is covered by water. Water makes life on Earth
possible. If life as we know it exists on some other planet, water must be
present to support that life.
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Section:
Interest Grabber continued
Section 2-2
1. Working with a partner, make a list of ten things that have water
in them.
2. Exchange your list for the list of another pair of students. Did your lists
contain some of the same things? Did anything on the other list surprise
you?
3. Did either list contain any living things?
Go to
Section:
Section Outline
Section 2-2
2–2
Properties of Water
A. The Water Molecule
1. Polarity
2. Hydrogen Bonds
B. Solutions and Suspensions
1. Solutions
2. Suspensions
C. Acids, Bases, and pH
1. The pH Scale
2. Acids
3. Bases
4. Buffers
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Section:
2-2 Properties of water
The water molecule
•Water is polar because there is an uneven
distribution of electrons between the oxygen
and hydrogen atoms.
•Hydrogen has a slightly positive charge
•Oxygen has a slightly negative charge.
•The attraction between the hydrogen atoms of
one water molecule and the oxygen molecule of
another water molecule is an example of a
hydrogen bond
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Section:
2-2 Properties of water
The water molecule
The 3 properties of water are:
1. Cohesion: attraction between molecules of
the same substance
2. Adhesion: attraction between molecules of
different substances
3. Capillary action: movement through small
spaces due to cohesion and adhesion
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Section:
2-2 Properties of water
Solutions and suspensions
•A mixture is a material composed of 2 or more
elements of compounds that are physically
mixed together but not chemically combined.
•The 2 types are solutions and suspensions
•A solution is a mixture of 2 or more substances
in which the molecules of the substances are
evenly mixed
•An example of a solution is saltwater.
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Section:
Figure 2-9 NaCI Solution
Section 2-2
ClCl-
Na+
Na+
Water
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Section:
Water
Figure 2-9 NaCI Solution
Section 2-2
ClCl-
Na+
Na+
Water
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Section:
Water
2-2 Properties of water
Substances in a solution
Substance
Definition
Solute
Substance that is Table salt
dissolved
Solvent
Substance in
which the solute
dissolves
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Section:
Example in a
saltwater solution
water
2-2 Properties of water
Solutions and suspensions
•The greatest solvent in the world is water
•A suspension is a mixture of water and nondissolved substances that are so small they do
not settle out
•An example is blood
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Section:
2-2 Properties of water
Acids, Bases and pH
•An acid is any compound that forms H+ (positive
hydrogen) ions in a solution.
•A base is any compound that forms OH- (Negative
hydroxide) ions in a solution.
•A compound is neutral if it produces equal number of
H+ and OH- ions.
•Water is neutral
•H2O↔H+ + OH•H+ + H2O ↔ H3O+
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Section:
2-2 Properties of water
Acids, Bases and pH
•Acids have a pH less than 7
•Bases have a pH greater than 7
•A neutral compound has a pH of 7
•Buffers are weak acids or bases that can
react with strong acids and bases to
prevent sharp, sudden changes in pH
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Section:
pH Scale
Section 2-2
Increasingly Basic
Oven cleaner
Increasingly Acidic
Neutral
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Section:
Bleach
Ammonia solution
Soap
Sea water
Human blood
Pure water
Milk
Normal
rainfall
Acid rain
Tomato
juice
Lemon juice
Stomach acid
Interest Grabber
Section 2-3
Life’s Backbone
Most of the compounds that make up living things contain carbon. In fact,
carbon makes up the basic structure, or “backbone,” of these compounds.
Each atom of carbon has four electrons in its outer energy level, which
makes it possible for each carbon atom to form four bonds with other atoms.
As a result, carbon atoms can form long chains. A huge number of different
carbon compounds exist. Each compound has a different structure. For
example, carbon chains can be straight or branching. Also, other kinds of
atoms can be attached to the carbon chain.
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Section:
Interest Grabber continued
Section 2-3
1. On a sheet of paper, make a list of at least ten things that contain
carbon.
2. Working with a partner, review your list. If you think some things on your
list contain only carbon, write “only carbon” next to them.
3. If you know other elements that are in any items on your list, write those
elements next to them.
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Section:
Section Outline
Section 2-3
2–3
Carbon Compounds
A.
B.
C.
D.
E.
F.
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Section:
The Chemistry of Carbon
Macromolecules
Carbohydrates
Lipids
Nucleic Acids
Proteins
2-3 Carbon Compounds
The chemistry of carbon
•Carbon has 4 valence electrons
•A carbon atom can bond to other
carbon atoms so they can forms
chains that can be almost unlimited
in length.
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Section:
Figure 2-11 Carbon Compounds
Section 2-3
Methane
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Section:
Acetylene
Butadiene
Benzene
Isooctane
2-3 Carbon Compounds
Macromolecules
•Many of the molecules in living cells are so large that
they are known as macromolecules
•A monomer is a small unit that can join with other small
units to form a polymer
•Monomers join together to form polymers
•This process is called polymerization
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Section:
Concept Map
Section 2-3
Carbon
Compounds
4 groups of organic
compounds
include
Carbohydrates
Lipids
Nucleic acids
Proteins
that consist of
that consist of
that consist of
that consist of
Sugars and
starches
Fats and oils
Nucleotides
Amino Acids
which contain
which contain
Carbon,
hydrogen,
oxygen
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Section:
Carbon,
hydrogen,
oxygen
which contain
which contain
Carbon,hydrogen,
oxygen, nitrogen,
phosphorus
Carbon,
hydrogen,oxygen,
nitrogen,
2-3 Carbon Compounds
Carbohydrates
•Made up of the element Carbon, Hydrogen and oxygen and
are usually in a 1:2:1 ration
•They are a main source of energy and structural.
•The monomer is a monosaccharide
•The three types of monosaccharides are glucose, fructose
and galactose
•Polysaccharides are large macromolecules formed from
monosaccharides
•The three are
starch-plant storage
cellulose-plant structure
gylcogen –animal storage
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Section:
Figure 2-13 A Starch
Section 2-3
Starch
Glucose
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Section:
2-3 Carbon Compounds
Lipids
•Lipids are mostly made up of the elements
carbon, hydrogen and oxygen
•The functions of lipids are store energy, serve
as part of membranes, and waterproof covering.
•Lipids are formed when glycerol combines with
fatty acids
•3 examples: fats, oils and waxes
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Section:
Lipids
2-3 Carbon Compounds
Kind of lipid
Description
Saturated
All fatty acid
butter
carbons are joined to
another carbon by a
single bond
Unsaturated
At least one carboncarbon double bond
in a fatty acid
Olive oil
Polyunsaturated
More than one c-c
double bond in fatty
acid
Corn oil
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Section:
Example
2-3 Carbon Compounds
Nucleic Acids
•Made up of hydrogen, oxygen, nitrogen, carbon and
phosphorus.
•Their function is to store and transmit genetic
information
•They monomer is a nucleotide
•3 parts to the nucleotide: nitrogenous base, phosphate
group and 5-carbon sugar
•2 types are : Ribonucleic Acid (RNA) and
Deoxyribonucleic Acid (DNA)
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Section:
2-3 Carbon Compounds
Proteins
•Proteins are made up of the elements:
nitrogen, hydrogen, carbon and oxygen.
•Their functions are control rate of reactions,
transport substances in or out of cells, fight
disease, and form bones and muscles.
•Their monomer is the amino acid
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Section:
Figure 2-16 Amino Acids
Section 2-3
Amino group
Carboxyl group
General structure
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Section:
Alanine
Serine
Figure 2-16 Amino Acids
Section 2-3
Amino group
Carboxyl group
General structure
Go to
Section:
Alanine
Serine
Figure 2-16 Amino Acids
Section 2-3
Amino group
Carboxyl group
General structure
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Section:
Alanine
Serine
Figure 2-17 A Protein
Section 2-3
Amino
acids
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Section:
Interest Grabber
Section 2-4
Matter and Energy
Have you ever sat around a campfire or watched flames flicker in a
fireplace? The burning of wood is a chemical reaction—a process that
changes one set of chemicals into another set of chemicals. A chemical
reaction always involves changes in chemical bonds that join atoms in
compounds. The elements or compounds that enter into a chemical
reaction are called reactants. The elements or compounds produced by a
chemical reaction are called products. As wood burns, molecules of
cellulose are broken down and combine with oxygen to form carbon
dioxide and water vapor, and energy is released.
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Section:
Interest Grabber continued
Section 2-4
1. What are the reactants when wood burns?
2. What are the products when wood burns?
3. What kinds of energy are given off when wood burns?
4. Wood doesn’t burn all by itself. What must you do to start a fire? What
does this mean in terms of energy?
5. Once the fire gets started, it keeps burning. Why don’t you need to
keep restarting the fire?
Go to
Section:
Section Outline
Section 2-4
2–4
Chemical Reactions and Enzymes
A. Chemical Reactions
B. Energy in Reactions
1. Energy Changes
2. Activation Energy
C. Enzymes
D. Enzyme Action
1. The Enzyme-Substrate Complex
2. Regulation of Enzyme Activity
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Section:
2-4 Chemical reactions and enzymes
Chemical reactions
•A chemical reaction is a process that changes
one set of chemicals into another set of
chemicals by changing chemical bonds.
•The reactants are the elements or compounds
that enter into a chemical reaction
•The products are the elements or compounds
produced by a chemical reaction.
•On notes label reactants and products
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Section:
2-4 Chemical reactions and enzymes
Energy in reactions
•Energy is either released or absorbed
when chemical bonds are formed or
broken.
•Activation energy is the energy needed
to get a reaction started.
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Section:
Figure 2-19 Chemical Reactions
Section 2-4
Energy-Absorbing Reaction
Energy-Releasing Reaction
Activation
energy
Products
Activation energy
Reactants
Reactants
Products
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Section:
Figure 2-19 Chemical Reactions
Section 2-4
Energy-Absorbing Reaction
Energy-Releasing Reaction
Activation
energy
Products
Activation energy
Reactants
Reactants
Products
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Section:
2-4 Chemical reactions and enzymes
Enzymes
•A catalyst is a substance that speeds up the
rate of a chemical reaction
•An enzyme is a protein that acts as a biological
catalyst
•Enzymes speed up reaction by lowering the
activation energy of the chemical reaction
•Show video 2D
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Section:
Effect of Enzymes
Section 2-4
Reaction pathway
without enzyme
Activation energy
without enzyme
Reactants
Reaction pathway
with enzyme
Activation
energy
with enzyme
Products
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Section:
2-4 Chemical reactions and enzymes
Enzyme Action
•Substrates are the reactants of enzymecatalyzed reactions
•An active site is the site on the enzyme where
the substrate binds.
•The active site and substrates in an enzymecatalyzed reaction are often compared to a lock
and key because the active site and substrate
have complementary shapes and the fit is
precise.
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Section:
Figure 2-21 Enzyme Action
Section 2-4
Enzyme
(hexokinase)
Glucose
Substrates
Products
ADP
Glucose-6phosphate
Products
are released
ATP
Active site
Enzyme-substrate
complex
Substrates
are converted
into products
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Section:
Substrates
bind to
enzyme
Figure 2-21 Enzyme Action
Section 2-4
Enzyme
(hexokinase)
Glucose
Substrates
Products
ADP
Glucose-6phosphate
Products
are released
ATP
Active site
Enzyme-substrate
complex
Substrates
are converted
into products
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Section:
Substrates
bind to
enzyme
Figure 2-21 Enzyme Action
Section 2-4
Enzyme
(hexokinase)
Glucose
Substrates
Products
ADP
Glucose-6phosphate
Products
are released
ATP
Active site
Enzyme-substrate
complex
Substrates
are converted
into products
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Section:
Substrates
bind to
enzyme
Figure 2-21 Enzyme Action
Section 2-4
Enzyme
(hexokinase)
Glucose
Substrates
Products
ADP
Glucose-6phosphate
Products
are released
ATP
Active site
Enzyme-substrate
complex
Substrates
are converted
into products
Go to
Section:
Substrates
bind to
enzyme
Videos
Click a hyperlink to choose a video.
Atomic Structure
Energy Levels and Ionic Bonding
Covalent Bonding
Enzymatic Reactions
Video 1
Atomic Structure
Click the image to play the video segment.
Video 2
Energy Levels and Ionic Bonding
Click the image to play the video segment.
Video 3
Covalent Bonding
Click the image to play the video segment.
Video 4
Enzymatic Reactions
Click the image to play the video segment.
Go Online
Career links on forensic scientists
Interactive test
Articles on organic chemistry
For links on properties of water, go to www.SciLinks.org and enter the
Web Code as follows: cbn-1022.
For links on enzymes, go to www.SciLinks.org and enter the Web Code
as follows: cbn-1024.
Interest Grabber Answers
1. Give an example of solid matter.
Sample answers: books, desks, chairs
2. Give an example of liquid matter.
Sample answers: water, milk
3. Give an example of gaseous matter.
Sample answers: air, helium in a balloon
4. Is all matter visible?
No
5. Does all matter take up space?
Yes
Interest Grabber Answers
1. Working with a partner, make a list of ten things that have water in them.
Possible answers: bodies of water, rain and snow, soft drinks and other
beverages, juicy foods such as fruits, and so on.
2. Exchange your list for the list of another pair of students. Did your lists contain
some of the same things? Did anything on the other list surprise you?
Students’ answers will likely be similar, but not exactly alike.
3. Did either list contain any living things?
Students’ lists may include plants, animals, or other living things.
Interest Grabber Answers
1. On a sheet of paper, make a list of at least ten things that contain carbon.
Students will likely know that charcoal and coal contain carbon. They may
also list carbohydrates (starches and sugars), oil, gasoline, wood, or carbon
dioxide.
2. Working with a partner, review your list. If you think some things on your list
contain only carbon, write “only carbon” next to them.
Students will say that charcoal and coal contain only carbon. While these
materials do contain small amounts of other elements, such as sulfur, they
are composed mostly of carbon.
3. If you know other elements that are in any items on your list, write those
elements next to them.
Students may know that many carbon compounds also contain oxygen and/or
hydrogen.
Interest Grabber Answers
1. What are the reactants when wood burns?
Reactants are oxygen and cellulose.
2. What are the products when wood burns?
Products are carbon dioxide and water.
3. What kinds of energy are given off when wood burns?
Light and heat are given off. Some students may also mention sound (the
crackling of a fire).
4. Wood doesn’t burn all by itself. What must you do to start a fire? What does this
mean in terms of energy?
To start a fire, you must light it with a match and kindling. You are giving the
wood some energy in the form of heat.
5. Once the fire gets started, it keeps burning. Why don’t you need to keep
restarting the fire?
Once the fire gets going, it gives off enough heat to start more of the wood
burning.
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