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