Chapter 6
Elements
1.Elements: is a substance that can’t
be broken down into simpler chemical
substances.
A. The 4 main elements found in
living things: C,H,O,N
Chapter 6
Elements
1. Carbon: long carbon chains
make up the backbone for Proteins,
Lipids, Carbohydrates, and Nucleic
Acids. *Any molecule that contains
carbon is called an organic
molecule.
Chapter 6
Elements
2 and 3. Oxygen and Hydrogen
are also found in Proteins, Lipids,
Carbohydrates, and Nucleic acids, as
well as make up water.
4. Nitrogen is found in both
Proteins and Nucleic Acids.
Chapter 6
2. Atom: the smallest particle of an
element that has the characteristics
of that element.
Chapter 6
ATOMS BOND TOGETHER TO FORM
COMPOUNDS
COMPOUND: A substance that is
composed of atoms of two or more
different elements that are chemically
combined. Ex. H20, water is made up
of Hydrogen and Oxygen.
2 H+O= H2O
Writing Chemical Formulas:
2H2 +O2  2H2O
Reactants
Products
A. The number in front of the atom or
molecule tells you how many of each
you have.
B. The subscript number tells you how
many of that kind of atom is in a
certain molecule.
Types of Bonds:
1. Covalent Bonds: When two atoms
share an electron to form a bond. Ex.
H2O
A. Molecule: a group of atoms held
together by covalent bonds.
Types of Bonds:
2. Ionic Bond: a bond where one
positively charged ion takes an
electron from a negatively charged
ion. Ex. Na+and Cl- form NaCl
Types of Bonds:
3. Hydrogen Bond: a weak magnetic
bond between the opposite poles of
two polar molecules: Ex. Water
A. Water is Polar because electrons
shared in covalent bonds of
molecules are not always shared
equally resulting in a polar molecule
with a partial positive pole and a
partial negative pole.
Types of Bonds:
B. Polar Molecule: a molecule with
an unequal distribution of charge. Ex.
H2O.
As a result of this polarity:
*Water can dissolve many ionic
compounds. Ex. Salt and Sugar
**Water molecules attract other water
molecules, forming a Hydrogen
Bond. This gives Water great
stability.
***Hydrogen Bonds Also helps hold
together many large molecules, such
as proteins and DNA.
ORGANIC MACROMOLECULES
Atoms bond together to form
Molecules and then Molecules bond
together to form Polymers.
1. Polymer/Macromolecule: is a large
molecule formed when smaller
molecules bond together.
* The four macromolecules that
make up living things are:
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic Acids
I. Carbohydrate: is an organic
compound made of C,H, and O with a
2:1 Hydrogen : Oxygen ratio.
1. Molecular Building Blocks:
Monosacharides (simple sugars)
like glucose and fructose bond
together to form Polysaccharides
(complex carbohydrates and
starches).
Monosaccharide (Monomer)
Disaccharides
Disaccharides
Polysaccharide (Polymer)
2. Function: It is mostly used as a
source of energy for the body. Ex.
Mammals store food in the liver in the
form of glycogen, a glucose polymer.
3. Examples: Carbohydrates can
be found in pasta, potatoes, cereal,
anything made of grain or corn, and
simple sugars.
II. Lipids: organic compounds that
have a large proportion of C-H bonds
and less oxygen than carbohydrates.
1. Molecular Building Blocks:
Glycerol (Alcohol)
Fatty Acids
2. Function: Cell use lipids for
energy storage, insulation, and a
protective coating.
Lipid Structure
3. Examples: Lipids can be found in
oils, butter and other dairy products,
meat products, and nuts.
III. Protein: A large complex polymer
made of C, H, O and N.
1. Molecular Building Blocks: Amino
Acids are the Building blocks of
protein. There are 20 in nature.
Amino Acid + Amino Acid etc…=
Protein
A. Peptide Bonds: The covalent
bonds between Amino Acids in a
protein.
2. Function:
A. Proteins provide the structure for
living things (Growth and Repair)
B. Proteins called Enzymes speed
up and controls all of the chemical
reactions in living things.
C. Enzymes can become denatured
(damaged) and as a result, stop
working when exposed to too high or
too low temperatures and pH.
* Acids and Bases:
ph: is a measure of how acidic or basic a
solution is. The scale ranges from 0-14. A
pH of 7 is neutral
Base: any substance that forms hydroxide
ions (OH-) in water and has a pH above 7
with 14 being the most basic.
Acid: any substance that forms hydrogen
ions (H+) in water and has a ph below 7
with 0 being the most acidic.
Examples of pH and Temperature
affecting Enzymes:
Temp: Human enzymes work best at a
temperature around 98.6 degrees F.
High fevers can denature enzymes,
slow down chemical reactions, and
as a result, even kill the individual.
pH: Pepsin a human stomach enzyme
works best at a pH of 2 but don’t work
in the Small Intestine with a pH of 8.
3. Examples: Proteins can be found in
meat, beans, nuts, eggs etc…
IV. Nucleic Acids: a complex molecule
that stores cellular information in the
form of a code. Ex. DNA and RNA. 1.
1. Molecular Building Blocks:
Nucleotides: The building blocks of
Nucleic Acids.
2. Function: They store information
in code and contain all of the
instructions used to form all of an
organism’s enzymes and structural
proteins.
DNA  RNA  Protein  Trait
Organic
Macro
Molecule/
Polymer
Carbohydrate
Molecular
Building
Blocks
Function in
Living Things
How to Detect
Monosacharides
Energy
Sugar: Brick-Red
Precipitate in
Benedict’s solution
Starch: Iodine (BlueBlack)
Lipid
Energy Storage
Glycerol
Insulation
and
Protection
Fatty Acids
Structure and
Amino
Control Chemical
Acids
Reactions
Protein
Nucleic Acid Nucleotides
DNA  RNA
Protein Trait
Translucent
Brown Paper
Bag
Biuret’s
solution turns
purple
Organic Macro
Molecule/ Polymer
Molecular
Subunits/
Monomer
Function in
Living Things
Foods
1.
A.
B.
D.
2.
A.
B.
D.
3.
A.
B.
D.
4.
A.
B.
D.