All organic molecules contain the element carbon. All living
things are composed of water, and organic molecules.
•Organic compounds contain carbon atoms that are
covalently bonded to other elements
•The structure of a biomolecule will help determine
its properties and functions
Carbon is a special element,
because it has four electrons
in its valence level to share.
It can form four covalent
bonds because of this.
There are four main groups of biomolecules. They are:
• Nucleic Acids
A biomolecule is any molecule that is
produced by an organism
The simplest organic compounds contain molecules composed of
carbon and hydrogen…also known as “hydrocarbons”.
The compound methane contains one
carbon bonded to four hydrogens.
In chemistry we use a molecular
formula to show how many atoms of
each element are present in a
A molecular formula does not show
the structure of the molecule.
Scientists often use structural
formulas to show the number and
arrangement of atoms in a
Fossil Fuels are hydrocarbons.
What are the four groups of organic
molecules we need to know about?
Why isn’t water an organic molecule?
What element does methanol and ethanol
contain, that other hydrocarbons don’t?
Carbohydrates are biomolecules that are composed of carbon,
hydrogen, and oxygen in approximately a ratio of 1:2:1
Carbohydrates include sugars (monosaccharides, and
disaccharides) starches (polysaccharides), and complex
polysaccharides like cellulose and glycogen.
• The most abundant of the
• a key source of energy
• found in most foods
The building blocks, or
monomers of carbohydrates
are single sugars called
Lipids are large biomolecules composed mainly of
carbon and hydrogen, with small amounts of oxygen.
They are nonpolar molecules that are not soluble in
water. Types of lipids include:
– Are lipids that can store a great deal of energy
–Contains three fatty acids bonded to a glycerol molecule
backbone (don’t worry…I’ll show you this)
•Other lipids include some light-absorbing
compounds called pigments
1) Polarity- lipids are non-polar and so are
insoluble in water, meaning they must be
stored in cells in special ways.
2) High-energy store - they have a higher
proportion of H atoms relative to O atoms
and so yield more energy than the same
mass of carbohydrate
3) Thermal insulation – fat conducts
heat very slowly so having a layer
under the skin keeps metabolic heat in.
4) Electrical insulation – the myelin
sheath around axons prevents ion
leakage, and increases signal speed.
5) Waterproofing – waxy cuticles are
useful, for example, to prevent excess
evaporation from the surface of a leaf.
1 gram of fat provides 9 kcal while 1
gram of carbohydrate or protein
provides 4 kcal
6) Hormone production – steroid hormones. Estrogen requires lipids for its
formation, as do other substances such as plant growth hormones.
Since lipids are indeed, not polymers, but
macromolecules made of many different
subunits…they do NOT contain monomers.
And since each type of lipid contains a different
set of building-blocks, what you need to know is
that lipids are composed of subunits known as
glycerol, and fatty acids.
Since there are three
fatty acids joined to this
glycerol molecule, it is
known as a triglyceride.
Place carbohydrates in order from smallest to largest in
terms of molecular size.
What are the monomers of carbohydrates?
How do lipids and carbohydrates vary in their structure?
What are three types of lipids?
Which lipids store the most energy?
• Proteins have many
structures, resulting in
a wide range of
• Proteins do most of the
work in cells, such as
• The monomers of
proteins are called
• Enzymatic Proteins
• Structural Proteins
• Storage Proteins
• Transport Proteins
• Hormonal proteins
• Receptor proteins
• Contractile and motor proteins
• Defensive proteins
Actin and Myocin
Enzymes catalyze the
hydrolysis of food
What are the monomers of proteins?
What is the primary structure of a protein?
Describe one job that proteins do.
The nucleic acids
include the amazing
It is the source of
species, and is the
foundation for the
unity and diversity of
all life on Earth.
• Nucleic acids store and
The amino acid sequence of a polypeptide is
programmed by a unit of inheritance called a gene
Genes are made of DNA, a nucleic acid
• Are the units of inheritance
• Program the amino acid sequence of
• Are made of specific nucleotide sequences on
Monomers of Nucleic Acids are called Nucleotides
The Roles of Nucleic Acids
• There are two types of nucleic acids involved in
inheritance and protein synthesis
– Deoxyribonucleic acid (DNA)
– Ribonucleic acid (RNA)
– Stores information for the synthesis of
– Found in the nucleus of cells
– Directs RNA synthesis (transcription)
– Directs protein synthesis through RNA
– Single stranded nucleic acid which
carries the code for protein synthesis
– Found in nucleus, and outside of
nucleus in association with ribosomes
Another type of nucleic
acid is ATP.
It is a source of energy
What are two functions of nucleic acids?
What are monomers of nucleic acids known