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 Perform most cell functions

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