THE MOLECULES
OF LIFE
ORGANIC MOLECULES

FOUR MAIN CATEGORIES:
carbohydrates: fuel & building material
lipids: fats & oils
proteins: perform most cell functions
nucleic acids: information storage
CARBON IS THE
MAIN INGREDIENT
OF ORGANIC
MOLECULES
ORGANIC vs. INORGANIC


Carbon based molecules are called
organic molecules (primary
exception is CO2)
Non-carbon based molecules—
water, oxygen, and ammonia (NH4)
are inorganic molecules.
Atomic Structure of Carbon



Carbon atoms can
form four bonds
Connecting point
for other atoms in
four directions
Can produce
endless variety of
carbon skeletons
that can bond with
carbon or with
other elements
CARBON SKELETONS
CARBOHYDRATES
PROVIDE FUEL
AND BUILDING
MATERIAL
CARBOHYDRATES ARE MADE
UP OF SUGAR MOLECULES

Sugars contain carbon, hydrogen,
and oxygen in the following ratio:
1 carbon : 2 hydrogen : 1 oxygen


Molecular formula of any
carbohydrate is a multiple of the
basic formula CH2O
Glucose (primary energy source for
all cells) is C6H12O6
HOW CELLS USE SUGARS


Main fuel supply for cellular work
Other uses:
- Provide raw material to make other
organic molecules such as fats
- Used to make energy stockpiles
- Serve as building materials
LIPIDS INCLUDE
FATS AND
STEROIDS
LIPIDS

Commonly known as fats and oils
FUNCTIONS OF LIPIDS


Act as a boundary—they are a major
component of cell membranes
Circulate in the body acting as chemical
signals to cells—some are hormones

Used to store energy in the body

Act to cushion and insulate the body
PROTEINS
PERFORM MOST
FUNCTIONS IN
CELLS
FUNCTIONS OF PROTEINS

Form structures—hair, fur, muscles

Provide long-term nutrient storage

Act as chemical signals—hormones
NUCLEIC ACIDS
STORE
INFORMATION
IN DNA AND RNA
FUNCTIONS OF NUCLEIC ACIDS



Form DNA and RNA
Long chains of molecules (6 Billion in
humans)
Controls the functions of the cells and is
responsible for passing on inherited traits