6 MOST BIOLOGICALLY IMPORTANT ELEMENTS

•  CARBON (19%)

•  HYDROGEN (9%)

•  NITROGEN (5%)

•  OXYGEN (63%)

•  PHOSPHORUS (0.6%)

•  SULFUR (0.6%)

•  Carbon, Hydrogen and Oxygen account for 96% of our body mass.

•  Carbon, hydrogen, and oxygen are used by living things to make up their structural and functional existence.

•  Nitrogen, Phosphorus, and Sulfur are important components in proteins, enzymes, lipids and nucleic acids.

 NATURALLY OCCURRING ON THE EARTH  MOST IMPORTANT  NEED TO GAIN ELECTRONS  TEND TO FORM COVALENT BONDS  PRODUCE STABLE MOLECULES  TEND TO FORM BONDS WITH TWO OR

MORE ATOMS  TEND TO FORM COMPLEX MOLECULES

WHY THESE ELEMENTS ARE BIOLOGICALLY IMPORTANT

THE SIGNS OF LIFE LIVING THINGS…..

1. ARE HIGHLY ORGANIZED. -organization refers to the high degree of order within an organism’s internal and external parts

THE SIGNS OF LIFE

LIVING THINGS…..

2.  ARE HOMEOSTATIC. -homeostasis is the ability to maintain stable internal conditions even though external conditions are constantly changing

THE SIGNS OF LIFE

LIVING THINGS….

3.  TAKE ENERGY FROM THEIR ENVIRONMENT AND PROCESS IT. -also referred to as metabolism -is the sum of all chemical processes that occur in an organism

THE SIGNS OF LIFE

LIVING THINGS….. 4.  GROW AND DEVELOP.

-all living things grow and increase in size, due to the division and enlargement of cells -development is the process by which organism become a mature adult

THE SIGNS OF LIFE

LIVING THINGS….

5.  ADAPT TO THEIR ENVIRONMENT. -populations of living organisms evolve or change over time

THE SIGNS OF LIFE

LIVING THINGS….

6.  RESPOND TO STIMULI. -all organisms must be able to react to stimuli in their environment in order for them to stay alive

THE SIGNS OF LIFE

LIVING THINGS…..

7.  REPRODUCE THEMSELVES. -all organisms produce new organisms like themselves