Transcript No Slide Title

Section Outline

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
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Section:

Structure of the Atom-made of sub-atomic particles:
Section 2-2
a. Protons
- these positively (+) charged particles are found
only in the nucleus. They determine the identity of the atom.
The number of protons in the nucleus will never change.
b. Neutrons - these neutral particles have no charge (0).
They are only found in the nucleus. The number of neutrons
can change in atoms of elements.

c. Electrons - these negatively (-) charged particles are
found in energy levels outside the nucleus. They are likely
to be found in certain levels, but may change levels when
energy is absorbed or given off. The number of electrons
can change in atoms. ( P=E)
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
Section:
When electrons sit in certain energy levels they have different degrees of
stability. This determines the reactivity of certain atoms.
Elements - They consists of only one type of atom such as gold, nitrogen,
copper, etc. Their atoms are abbreviated with symbols
(Au, N, Cu)
Example: Na (sodium) It has only one electron in its outer energy level.
This make it very unstable, so it wants to combine with other elements to
stabilized. ( Its outer electron does not like to be alone!)
Atomic Number - (P) This is the number of protons in the nucleus. It
does not change and determines the atoms identity.
When P = 5 the element is B (boron)
Mass Number (atomic mass)- ( P + N) This is the number of protons and
neutrons in the nucleus.
Isotope - This is an atom of an element where the number of neutrons have
changed. ( Ex: hydrogen isotopes)
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Section:

Radioactive Isotopes The extra Neutrons can
cause the atoms to be unstable due to an imbalance
of positive charge and break down over time,
releasing radiation. They can also be used for many
things such as:

Sterilizing food
Treating diseases such as cancer
Tracer molecules for diagnosing diseases
Measure the age of certain old artifacts and rocks
(carbon dating)



Radioactive Isotopes
 When a nucleus breaks apart, it gives off
radiation that can be detected and used for
many applications. (dating, tracers, disease)
Two types of bonds: Ionic and Covalent
1. Ionic bonds - Electrons are given away or
taken by another atom in order to stabilize.
Ions are formed by each atom for this to take
place.
 Ions are simply atoms with a positive ( +) or
negative (-) charge.

2. Covalent Bonds- Electrons are shared by
atoms in order to stabilize.
 Van der Waals forces – attraction between
molecules due to opposite charges.

Section 2-1
An Element in the Periodic Table
6
C
Carbon
12.011
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Section:
Section 2-1
Figure 2-2 Isotopes of
Carbon
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
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)
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
Section Outline

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:
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
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Polarity
Universal solvent
Expands when solid
Covers most of the earth
What is it?

Polarity – one end is slightly + the other -.
Water molecules join other water molecules
in tight bonds.

This acts like a magnet to dissolve compounds
Water!
Section 2-2
Figure 2-9 NaCI Solution
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
Acids and Bases
 Substances that release hydrogen ions (H+) when
dissolved in water are called acids.
 Substances that release hydroxide ions (OH–)
when dissolved in water are called bases.
pH Scale
Oven cleaner
Increasingly Basic
Bleach
Acidic solutions
have pH values
lower than 7.
Increasingly Acidic
Neutral
Ammonia solution
Basic solutions have pH
values higher than 7.
Soap
Sea water
Human blood
Pure water
Milk
Normal
rainfall
Acid rain
Tomato
juice
Lemon juice
Stomach acid
*Neutralization = acid + base  water + a salt Link
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Section:
Mixtures: Two or more elements or compounds physically
combined.
 Ex:
koolaid
captain crunch
Soil
salad dressing
soda
Whipped cream
dust
Blood
Fog
metal alloys
chocolate milk
Two types of mixtures:
 Solutions – molecules of the solute (smaller amount)
uniformly spread into solvent (larger amount). Which of
the above items are solutions?

Suspension – solute does not dissolve in the solvent.
Settles over time. Name some from above.
Homogenous Mixtures (solution)
 A mixture that has a uniform
composition throughout
 A solvent is a substance in
which another substance is
dissolved.
 A solute is the substance
that is dissolved in the
solvent.
Food coloring dissolved in
water forms a homogenous
mixture.
Heterogeneous Mixtures or suspensions
 In a heterogeneous
mixture, the
components remain
distinct.
A salad is a heterogeneous mixture.
Section 2-3

Section Outline
2–3Carbon Compounds
A.The Chemistry of Carbon
B.Macromolecules
Section 2-1
C.Carbohydrates
D.Lipids
E.Nucleic Acids
F. Proteins
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Section:
6
C
Carbon
12.011
Would you like some Ethyl butyrane ice
cream?
 What is this?
“Pineapple” ice cream!
 Flavor comes from organic compounds.
 C, N, H, O - these elements make up
almost all chemical compounds in living
things.
 Carbon atoms can form long chains and
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rings.
Section:
Organic Chemistry
 The element carbon
is a component of
almost all biological
molecules.
 Carbon has four electrons in its outermost
energy level.
 One carbon atom can form four covalent bonds
 Carbon compounds can be in the shape of straight
chains, branched chains, and rings.
Concept Map
Section 2-3
Carbon
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,
Figure 2-11 Carbon Compounds
Methane
Acetylene
Butadiene
Benzene
Isooctane

Carbohydrates- made of C, H, O. Ratio of 2 hydrogen to 1 oxygen.
Function: energy source
a. Monosaccharides:simple sugar. (mono-single or one)
Examples:
Glucose –plant sugar
Fructose – fruit sugar
Galactose – milk sugar
Isomers –all three sugars listed above have the samemolecular
composition (C6 H12 O6 ), but are different in shape.
b. Disaccharides – double sugars. Two monosaccharides combined in a
condensation reaction to make a disaccharide.
Examples: Sucrose –table sugar (glucose + fructose)
Lactose –milk sugar (glucose + galactose)
Maltose – glucose + glucose
c. Polysaccharides – 3 or more monosaccharides joined from condensation
reactions.
3 types:
glycogen- animal storage of glucose. (animal starch)
Starch- plants store glucose in long chains and coils.
Cellulose – gives strength and structure to plants from chains of glucose.
Figure 2-13 A Starch
Section 2-3
Starch
Glucose
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Section:


Lipids (2nd type of organic
molecule)
A fat-like substance made of C, H, O
but has less oxygen than
carbohydrates. They do not dissolve
in water. Includes: fat, oils, waxes.

Cell membrane is made mostly of
lipids

Function: Lipids store energy very
well, due to the large # C-H

Lipids –made of many fatty acid
monomers.(units)

Fatty Acids- What are these?
Chains of C-H (hydrocarbons) with a
C-O-O- H (carboxyl group) at one
end. See P. 51. The two ends are
different.
-Polar end (carboxyl) attracted to
water.

Three types of lipids:
1. Triglycerides – made of 3 fatty acids joined
to one molecule of glycerol. Includes:
oils- liquid at room temperature (plants)
Fats- solid at room temperature (animals)

2. Wax – made of long fatty acid chain +
alcohol.Very waterproof.
3. Steroid – made of 4 carbon rings. Does
not dissolve in water. Includes: poisons,
hormones, etc.

Proteins – (3rd type of organic molecule) Made of C, H, O and N.
Made of amino acids hooked together (monomers). Important in life
process in plants and animals.
Amino Acids (AA) -piece that make-up proteins.

Differences in aa are due to different R-groups. 20 different aa exist.
Peptide bond –bonds which link peptides (aa)
Polypeptide – a long chain of many aa linked.
Enzymes – a special type of protein - acts as a catalyst to speed up chemical
reactions.
*Enzymes fit like “puzzle-pieces” to certain molecules, which are called
substrates.
Functions of Proteins:
Enzymes
support
Insulin
antibodies
muscle contraction
store nutrients
toxins
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:
Nucleic Acids – 4th type of organic
molecule.
 Function: - to store important
info in cell (genetic)
Two types:
1. DNA – (Deoxyribonucleic Acid) –
stores info in the cell to be used
for cell functions(brain of cell)
2. RNA – (Ribonucleic Acid) stores
and transfers information for
making proteins.
 Nucleotides – Pieces which make
up DNA and RNA
 Structure of nucleotides:
phosphate group (P)
5-Carbon sugar
Nitrogen base (N)
Section Outline
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:
Chemical equations
Section 2-4
Terms: reactants
Products
coefficients
subscripts
*Reactions are reversible
Ex: HCL --> H + + ClH+ + Cl - ---> HCl
C6 H12 O6 + C6 H12 O6 ---> C12 H22 O11 + 2H 2O
(glucose)
(fructose)
(sucrose)
(water)
Mg + F2 ---> Mg F2
H2 O --> O2 + H2
Some reactions are spontaneous, others require energy to begin.
Exothermic vs. Endothermic?
Gives off energy absorbs energy (in)
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Section:
Enzymes reduce the activation energy needed for reactions.
Effect of Enzymes
Reaction pathway
without enzyme
Activation energy
without enzyme
Reactants
Reaction pathway
with enzyme
Activation
energy
with enzyme
Products
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Section:
Section 2-4
Figure 2-19 Chemical Reactions
Energy-Absorbing Reaction
Energy-Releasing Reaction
Activation
energy
Products
Activation energy
Reactants
Reactants
Products
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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
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Section:
Substrates
bind to
enzyme