Chemistry of Life
At the Completion of this Unit, Students will be able to:
•List the major chemical elements in cells and know their chemical symbols
and explain why they are essential to life (i.e. carbon, hydrogen, oxygen,
nitrogen, phosphorus, sulfur, potassium, and trace elements)
•Explain the properties of water and describe why these properties are
important to life. (Cohesion, adhesion, less dense as a solid, heat capacity,
solvent properties, pH)
•Identify the function of the 4 groups of macromolecules, how they are
formed
•(Carbohydrates, proteins, lipids, nucleic acids) and describe their structure.
•Explain the role of enzymes in living organisms
A. Students will be able to identify and define the parts of an atom
What makes up the chemistry of
life? Adam or Atom

The study of chemistry begins with the basic unit of matter, the
atom.

The Greek word atomos,
 which means “unable to cut”.

This word was first used nearly 2500 years ago by Greek
philosopher Democritus.

Democritus asked a simple question “If you take an object like
chalk and break it in half are both pieces still chalk?”
Yes, suppose you break the chalk down again and again and
again. Can you continue to divide without limit? Or is there a
limit? Democritus thought there was a limit.
Democritus called the smallest fragment the atom, a name
scientists use today.


A. Identify and define the parts of an atom
Chemistry of Life
Atoms – the SMALLEST
particle that can exist and
still be considered a certain
kind of matter
 All LIVING and NONLIVING
things are made of atoms

A. Identify and define the parts of an atom
Atoms -- have three components



ELECTRONS -- negatively
charged
PROTONS -- positively
charged; found in nucleus
NEUTRONS -- neutral; found in
nucleus
A. Identify and define the parts of an atom
Electrons
Protons&
Neutrons
(Nucleus)
Energy
Levels
B. Demonstrate how to use the Periodic Table of Elements
B. Demonstrate how to use the Periodic Table of Elements
Atomic Number
= # of Protons and # of
Electrons
Chemical Symbol
Carbon
Chemical Name
Atomic Weight =
# of Protons + Neutrons
B. Demonstrate how to use the Periodic Table of Elements
Carbon
Atomic Number = # of Protons
and # of Electrons
Chemical Symbol
Chemical Name
Atomic Weight =
# of Protons + Neutrons
Remember: No more than
2 electrons on first ring,
No more than 8 on second
P=6
E=6
N = 6 (Atomic Weight – Atomic # = Neutrons)
Chemistry of Life
•
Elements -- a substance
that is made of only ONE
kind of ATOM
Major Elements of Life
•
•
•
•
•
C = Carbon
H = Hydrogen
O = Oxygen
P = Phosphorus
K = Potassium
Major Elements of Life
•
•
•
•
I = Iodine
N = Nitrogen
S = Sulfur
Ca = Calcium
Major Elements of Life
•
•
•
•
Fe = Iron
Mg = Magnesium
Na = Sodium
Cl = Chlorine
Where do we find these elements?
•
In all living and nonliving things.
Major Elements in Human Body
Chemistry of Life


Compounds – matter that is
made of more than ONE kind of
ATOM
Compounds are made by atoms
sharing or taking ELECTRONS
from the other atoms in the
compound
Compound Example

Water ( H2O ) – each
molecule is made of two
HYDROGEN atoms and
one OXYGEN atom
Water Molecule
Chemical Bonds

The main types of Chemical Bonds in a
compound are:
 Ionic Bonds
 Covalent Bonds
Ionic Bonds

An IONIC BOND is formed when one or
more electrons are transferred from one
atom to another.
Ionic Bond Example
Covalent Bonds

A COVALENT BOND is formed when
electrons are shared between atoms.

Single bond: Share two electrons
Double bond: Share four electrons
Triple bond: Atoms share six or more
electrons



MOLECULE. The structure that results when
atoms are joined together by a covalent bond.
Covalent Bond Example
The Water Molecule






One atom of oxygen binds to two atoms of hydrogen
to form H20.
Like all molecules a water molecule (H20) is neutral.
Water molecules are held together by a hydrogen
bond.
Hydrogen Bonds are not as strong as covalent or
ionic bonds.
The hydrogen atoms are attached to one side of the
oxygen atom, resulting in a water molecule having a
positive charge on the side where the hydrogen
atoms are and a negative charge on the other side,
where the oxygen atom is.
Since opposites attract, water molecules tend to
attract each other, making water kind of "sticky."
The Water Molecule
Add – Solute, solution, solvent, pH,
heat capacity
Properties of Water


Cohesion is an attraction between
molecules of the same substance.
- Example: molecules on the
surface of water are drawn inward,
forming drops and beads.
Properties of Water
Adhesion is an attraction between molecules
of different substances.
- Example: Water clinging to paper towel.
• Capillary action is one of the forces that
draws water out of the roots of a plant and up
into its stems and leaves.
(Cohesion holds the column of water
together as it rises)
•
Bell Work




Select 3 words off of your word wall
On the bottom of your word wallDefine the word by DRAWING the
meaning of the word
Example:
+
+
=
Cohesion
Why is water so important to
agriculture?
At least 75% of animal body
mass is water
 Plants contain 70-80% water
 Transports nutrients and
wastes

Why is water so important to
agriculture?

Dissolves compounds -“Universal Solvent”
 the liquid in which a solute is
dissolved to form a solution.
 Solute – the minor component
in a solution, dissolved in the
solvent
Why is water so important to
agriculture?


Regulates body
temperature in animals
Provides structure for
plants
E. Summarize the importance of water in agriculture.
What is this?
E. Summarize the importance of water in agriculture.
E. Summarize the importance of water in agriculture.
How much milk does she
produce daily?

80-100 pounds per day
 8 pounds per gallon
E. Summarize the importance of water in agriculture.
How much WATER does a milk
cow drink daily?

2 gallons of water to produce 1 gallon of
milk

Remember…
80-120 pounds per day

 8 pounds per day

20-30 gallons
F. Identify the function of the four major macromolecules.
Macromolecules=
A Very Large Molecule – made up of
smaller organic molecules.
Remember…
Molecules are structures that are made when
atoms are joined by a covalent bond.
Vs.
F. Identify the function of the four major macromolecules.
4 Classes of Macromolecules
Carbohydrates
Proteins
Lipids
Nucleic Acids
Carbohydrates


Provide energy
Three Types
 Monosaccharides
 Disaccharides
 Polysaccharides
Carbohydrates
Monosaccharaides



simple SUGAR
contain C6H12O6
GLUCOSE, FRUCTOSE, AND
GALACTOSE
Carbohydrates
Disaccharides



double SUGAR
contain two RINGS
SUCROSE and LACTOSE
Carbohydrates
Polysaccharides



complex CARBOHYDRATES
made of RINGS of SUGAR
STARCH, CELLULOSE, and
GLYCOGEN
Proteins


STRUCTURE and FUNCTION
Made of H, O, C, N
Structure of Proteins

Amino Acids – building BLOCKS
20 different kinds – all have the same
elements but in different amounts
Polypeptides – chains of AMINO ACIDS
Joined by peptide bonds
 Proteins – chains of POLYPEPTIDES
 Used to make SKIN, HAIR, MUSCLE,
ORGANS, etc.

Carbon
Atoms
Beef
Chemical
Bonds
Protein
Lipids
FATTY molecules
 used to store ENERGY
 Made of long chains of H & C
followed by COOH
 Do not DISSOLVE in WATER
 Lipids have less OXYGEN than
carbohydrates
 Examples of Lipids are: FATS, OILS,
AND WAXES

Nucleic Acids
Store INFORMATION that controls
CELL activities
 Made of a PHOSPHATE a SUGAR,
and a BASE.
 Examples of Nucleic Acids are: DNA
and RNA

Enzymes
Cells use enzymes to speed up
chemical reactions that take place in
cells.
 Enzymes must collide with enough
energy to break bonds creating a
chemical reactions.
 Chemical reactions create energy.

Bell Work-Charades!




Select 2 words off of your word wall
Select a partner to work with
“Act” out the words you’ve selected to
your partner until they guess
Remember Charade Rules
– No Talking
– No spelling the words (sign language)
Molecule Structure
Protein
Lipids
Nucleic Acid
Michelangelo E-Moment
1.
2.
3.
When you hear the word “JUMP” you
will proceed to the front of the
classroom in an orderly manner to get
enough gumdrops and toothpicks to
create a model of an atom.
Think carefully about what you will
need. What questions are there?
JUMP
n
n
n
n
n
n
n
n
Be sure to cover all the basic points about enzymes:
Enzymes are biological catalysts that speed up the chemical reactions
of the cell.
Enzymes are proteins.
Enzymatic reactions occur faster and at lower temperatures because
enzymes lower the activation energy for that chemical reaction.
Enzymes are never consumed or used up during the reaction. They
can do their job over and over again.
Enzymes are highly specific for just one substrate. The enzyme has an
active site with a unique 3-D shape into which this substrate must fit.
Enzymes catalyze both the forward and the reverse of the same
reaction.
Enzymes can be denatured by temperatures and pH levels outside the
optimal range for that particular enzyme.
Enzymes are truly amazing proteins that play a vital role inside every
living cell. Please don't leave this out of your curriculum!