Chapter 6 Notes
The Chemistry of Life
Section 6.1 Atoms and Their Interactions
Take 5:

____________ is the condition that
results from changes in the independent
variable.

__________ results in an increase in the
amount of living material and the
formation of new structures.
Take 5

An atom of Fluorine has nine electrons. Its
second energy level has ________
electrons.

How many electrons can a carbon atom
share?

What kind of bond is formed when two
atoms share electrons, such as with hydrogen
and oxygen in water?
Take 5

Water dissolves many ionic and molecular
compounds because of its __________.

Show the bond between magnesium and
Sulfur.

Name two types of carbohydrates.
Take 5

What are the two components of a lipid?

What are the 3 components of a
nucleotide?

What do nucleotides make up? Give 2
examples….
Take 5

Draw Neon and show the energy levels.

Show me a covalent bond between two
carbon atoms.

Show me an ionic bond between NaCl
I. Elements
A.
Natural elements in living things
1. Element= _________________________
A substance that can’t be broken
down into simpler chemical substances.
________________________________
9 6 % of the mass
2. Four elements make up ______
C, H, O , N
of the human body: _________________
3. Look at page 142, Table 6.1. It shows some
common elements along with their symbols,
found in the human body.
Elements in the Human Body
I. Elements
Trace Elements
Elements that play a vital role in maintaining
= ______________________________
healthy cells, but are needed in very small amounts
________________________________
(Table 6.1)
B.
II. Atoms: The Building Blocks of Elements
Atom= the smallest particle of an
Element
__________
that has the characteristics
of that element.
A. The structure of an atom

1. The center of an atom is the
Nucleus
___________.
Protons
2. The nucleus is made up of _________
(p+)
which are positively charged and
__________
Neutrons (n) which are neutral or have
no charge.
II. Atoms: The Building Blocks of Elements
3. Elements are arranged on the Periodic
table according to the number of
Protons
________ they naturally have. This number
Atomic ____________.
Number
is called the __________
4. The region of space surrounding the
nucleus contains extremely small, negatively
Electrons
charged particles called __________
(e-).
This region is also known as the
Electron ___________.
Cloud
__________
 Atomic Number for
Carbon=
Therefore,
there are 6 protons in the
nucleus.
How many Protons are in the following
Elements???
Helium
Calcium
Neon
He = 2
Ca = 20
Ne = 10
II. Atoms: The Building Blocks of Elements
B.
Electron energy levels (pg. 143, fig 6.2)
1. Within the electron cloud, there are energy
levels which the electrons move in.
E1= 2 electrons
E2= 8 electrons
E3= 18 electrons
E4= 32 electrons
Draw the energy levels of each atom:
Nitrogen
Iron (Fe)
III. Isotopes of an Element
Isotope = atoms of the same element that have
protons but a different
the same number of ________,
Neutrons
number of ___________.
2. Scientists refer to isotopes by stating the
protons
combing total of ___________
and
__________
Neutrons in the nucleus.
3. For example: Carbon-12 (naturally occurring
element)
Carbon-14 (contains 2 more
neutrons)
unstable
- The nucleus is ___________
and tens to break
apart and give off ______________.
radiation
1.
IV. Compounds and Bonding
Compound = a substance that is
atoms
composed of ________
of two or more
different
__________
elements that are
Chloride
chemically combined. Ex: NaCl Sodium
_______
 How and why do elements combine?
Atoms
combine with each other only when the resulting
_______________________________
compound is more stable than the individual atoms.
________________________________
 For many elements, an atom becomes
stable
________
when its outermost energy
full
 level is __________.

IV. Compounds and Bonding
A.
How covalent bonds form
The force between two atoms
1. Covalent Bond = _____________________
that share electrons
2. The electrons being shared ____________
move
around both elements holding them
___________
together
close
molecule
3. A ________________
is a group of atoms
held together by covalent bonds. Ex:
H2 O
____________
(_______)
water
IV. Compounds and Bonding
4.
Examples of covalent bonds:
a. Two hydrogen atoms
IV. Compounds and Bonding
b. Two Carbon Atoms:
IV. Compounds and Bonding
B.
How ionic form
1. Ionic bond= _______________________
The attractive force between two
ions of opposite charge
___________________________________
charged atom that gained or lost electrons
2. Ion = A____________________________
less
3. These bonds are ________
abundant in living
things than covalent molecules, but ions are
biological
important in _________
processes
4. Examples of ionic bonds:
IV. Compounds and Bonding
A. Table salt NaCl:
Na = 11
Cl = 17
B. MgS:
Mg = 12
S = 16
V. Chemical Reactions
bonds
Chemical reactions occur when ______
are formed or broken, causing substances
recombine into different substances.
to __________
 All the chemical reactions that occur
within an organism are referred to as that
metabolism
organism’s ________________.
A.Writing chemical equations

1. Basic Setup:
_________
Reactants _________
Products
Na+Cl  NaCl
V. Chemical Reactions
2. In chemical reactions, it is important to
understand that atoms are neither
_________
nor __________,
they are
created
destroyed
simply rearranged.
VI. Mixtures and Solutions
Mixture = a combination of substances in
which the __________
components retain
individual
properties
their own __________.
Ex:
_________________________
Mixing
sand and sugar, salt and pepper
 Solution = a mixture in which one or more
substances (solutes) are distributed
_________
_________
in another substance (solvent).
evenly
In other words, one substance is
dissolved
__________
in another and will not settle
out of solution.
and water, food coloring and water
 Ex: Sugar
_____________________________

A.
VI. Mixtures and Solutions
Acids and Bases
1. Chemical reactions can only occur when
conditions are __________.
One condition
right
that is very important is the ____
pH of the
solution.
2. The pH is a measure of how _________
or
acidic
_________ a solution is.
basic
3. Look on page 150, fig 6.11 for the pH scale
____________
is acidic, ________
is neutral,
0 to 6
7
________
is basic.
8-14
4. An acid is any substance that forms hydrogen
 (H+) + (Cl-)
ions (H+) in water. EX: HCl
_________________
VI. Mixtures and Solutions
5. A base is any substance that forms
hydroxide ions (OH-) in water
NaOH  (Na+) + (OH-)
EX: ___________________________
6. If the hydrogen ions equal the hydroxide
ions the solution is neutral and the pH of 7.
7. So……………
If H+ > OH- then solution is acidic
If H+ < OH- then solution is basic
If H+ = OH- then solution is neutral
pH of common substances
Concentration of H+ ions
Section 6.2
Water
I. Water and Its Importance
A.
Water is polar
A molecule with unequal
1. Polar Molecule= ____________________
distribution
of charge
__________________________________.
Positive
2. These molecules have a __________
end
negative
and a ______________.
3. Polar molecules attract other __________
polar
molecules as well as _________
Charged ________
ions
4. Look at page 153, fig 6.12. Water is a polar
molecule.
I. Water and Its Importance
When two water molecules come in close
contact, the negative ___________
end is
oxygen
attracted to the other water molecules
positive ___________
end. This
hydrogen
attractions of opposite charges forms a
weak
Hydrogen bond
________
bond called a ____________.
Because of water’s polarity, it…..
5.
6.
-
Is the ____________
Universal ____________
solvent
Can move up plants by ________
Capillary________
action
Water is a
universal
solvent!!!!!
I. Water and Its Importance
B.
Water resists temperature changes
more heat to increase its
1. Water requires ______
temperature than other liquids. Why?
Because of__________________________________
the hydrogen bonds between each molecule. As
__________________________________
you heat up
water, the bonds must be broken to move around.
2. When water cools, it gives _____
a lot of
off
___________.
heat
3. Because water takes longer to heat up and
cool down, it is like an _______
insulator that helps
steady
maintain a __________
environment when
conditions fluctuate outside and within our
own ______________.
Bodies/cells
I. Water and Its Importance
C.
Water expands expends when it freezes
- As water begins to freeze
_________ more and more
_____________bonds are formed and the water
hydrogen
molecules become more ________
spread apart. When
this happens as a piece of ice forms, it becomes
Less dense
________
________ than the surrounding liquid
water, therefore ice ___________________!
floats
II. Diffusion
A.
B.
Early observations: Brownian motion
Just
Know
andofunderstand
the definition
(1827)
Was one
the first to observe
the random
of molecules and substances.
ofmotion
Diffusion!!!!!
The process of diffusion
1. Diffusion= ________________________
The net movement of particles from an
area of higher concentration to an area of lower
___________________________________
concentration.
slow
2. Diffusion is a ___________
process because it
relies on the random _________
motion of atoms and
molecules
Diffusion
Section 6.3
Life Substances
I. The role of Carbon in Organisms
A.
Molecular Chains
organic
1. Biomolecule = large ____________
compounds ( contains 10’s, 100’s, to 1000’s
of carbon atoms)
2. Polymer = a large molecule formed when
________
smaller molecules bond together.
many
I. The role of Carbon in Organisms
B.
The structure of carbohydrates
1. Carbohydrate = a biomolecule composed of
________________________________
carbon,
hydrogen, and oxygen that has or can
be reduced to a 1:2:1 ratio
_____________________________
(C:H:O
ratio)
2. Functions of carbos: ___________________
Stores energy for the cell
3. Two types of carbohydrates:
a.
_______________
Sugars
-
A _______________
(small) sugar
simple
monosaccharide is a ____________
EX: glucose and fructose
I. The role of Carbon in Organisms
-
A Disaccharide
__________ is _____
monosaccharide's linked
2
together
EX: glucose + fructose = sucrose (table sugar)(pg 159,
6.17)
Starches
b. _______________
polysaccharides The are polymers
- Starches are ________________.
-
composed of many monosaccharide subunits.
EX: glycogen + cellulose (pg 159 6.17)
Carbohydrate- sugar
Monosaccharide
Glucose is stored:
1. In a plant as
starch
2. In an animal as
glycogen
The formula for glucose (C6H1206) is shown
above. (1:2:1)
I. The role of Carbon in Organisms
C.
Structure of Lipids
1. Lipid= large biomolecules that __________
are made
mostly of carbon and hydrogen with a small
___________________________________
amount of oxygen.
It can ______
reduced to a 1:2:1 ratio
not
Insoluble in water because their
2. The are _________
molecules are __________
nonpolar and repel water
Fats, oils, waxes, and steriods
3. EX: _____________________________
___________________________________
energy storage,
4. Functions of lipids: __________________
insulation, protective coverings
__________________________________
I. The role of Carbon in Organisms
5. Components of a lipid:
Three fatty acids
a. ________________________
one glycerol molecule
b. ___________________
(pg 160, 6.2)
6. Lipids can be saturated, unsaturated, or
polyunsaturated.
carbon atoms
- Saturated = All of the ______
are _______
bonded together; the molecule
Single
saturated
is now ____________
with hydrogen atoms
I. The role of Carbon in Organisms
◦ Unsaturated = when a _______
double bond exists
between two of the carbon atoms; the
molecule now has ________
hydrogen atoms
less
◦ Polyunsaturated = when _________
double
many
bonds exist between the carbons; even
__________
hydrogen is present now.
less
D.
The structure of proteins
1. Protein=
A large,
complex polymer composed of
________________________________
carbon, hydrogen, oxygen, nitrogen, and
___________________________________
sometimes sulfur.
I. The role of Carbon in Organisms
2. Components of a protein: __________
Amino acids
___________________________
3. The amino acids are linked together by
covalent ___________
bonds.
peptide
shapes
4. Proteins come in a large variety of _______
and _________.
The number and order of the
sizes
____________
Amino acids determines its function.
Hair,
5. Functions of proteins:
fingernails,
support
horns, hoofs
a. Gives structure and ____________.
Ex: _________
muscles
b. Help ____________
contact.
I. The role of Carbon in Organisms
c.
oxygen
Transport ____________
in your bloodstream.
hemoglobin
Ex: ______________
d. Provide ______________
EX: _____________
antibodies
immunity
e. Carry out ______________
EX: ___________
reactions
enzymes
6.
An _____________
is a protein that
enzyme
rate
changes the __________
of a chemical
reaction.
- Without the ________
of enzymes, we would
help
not be able to __________
our food fast
digest
enough to feed our body.
I. The role of Carbon in Organisms
E.
The structure of nucleic acids
1. Nucleic acid = a complex biomolecule that
Store
cellular information in the form of a code
________________________________.
2. Components of a nucleic acid:
nucleotide
______________
(which have C, H, O, N, & P)
3. A nucleotide is made up of: (page 163, fig 6.24)
sugar
a. ________________________
Nitrogenous base
b. ________________________
Phosphate group
c. ________________________
I. The role of Carbon in Organisms
4. Examples:
a. _______
DNA (deoxyribonucleic acid)
- Contains our __________
________ ( how to
Genetic code
make all of our proteins)
b. ______
RNA (ribonucleic acid)
- Take the code from ______
DNA and actually take part
in making our ______________.
proteins