Download 4 Necessities of Life

4 NECESSITIES OF LIFE
WATER
• Your cells and the cells of almost all living organisms are
approximately 70% water. Most of the chemical reactions involved
in metabolism require water.
AIR
• Air is a mixture of several different gases, including
oxygen and carbon dioxide. Most living things use oxygen
in the chemical process that releases energy from food.
PLACE TO LIVE
•All organisms need a place to live that contains all of the
things they need to survive. Space on Earth is limited, so
organisms are often in competition with each other.
FOOD
•
gives organism energy and the raw material needed to
carry on life processes.
• Making Food
•Producers can make their own food by using energy
from their surroundings (ex. Plants)
• Taking Food
•Consumers must eat (consume) other organisms to
get food.
• Decomposers are consumers that get their food by
breaking down the nutrients in dead organisms or
animal wastes.
PUTTING IT ALL TOGETHER
•
All organisms need to break down that food in order to use the
nutrients in it.
•
Nutrients are made up of molecules.
•
Molecules found in living things are usually made up of six
elements: carbon, hydrogen, nitrogen, oxygen, phosphorus, and
sulfur.
PROTEINS
• large molecules made up of amino acids.
• Making Proteins
• Organisms break down the proteins in food to supply their cells with
amino acids that are then linked together to form new proteins.
• Proteins in Action
• Some form structures that are easy to see
• Some help cells do their jobs
• Some are called enzymes and they start or speed up chemical
reactions in cells.
CARBOHYDRATES
•
Molecules made of sugars
• Simple Carbohydrates
• made up of one sugar molecule or a few sugar molecules
linked together.
• Complex Carbohydrates
• made of hundreds of sugar molecules linked together
• organisms store extra sugar as these
LIPIDS
compounds that cannot mix with water.
• Phospholipids
• molecules that form much of the cell membrane.
• Fats and Oils
• lipids that store energy
• when an organism has used up most of its carbohydrates, it
can get energy from these lipids.
ATP (ADENOSINE TRIPHOSPHATE)
• the major energy-carrying molecule in cells.
• The energy in carbohydrates and lipids must
first be transferred to ATP, which then
provides fuel for cellular activities.
NUCLEIC ACIDS
• large molecules made up of subunits called nucleotides.
• sometimes called the blueprints of life because they have
all the information needed for a cell to make proteins.
• DNA is the most important nucleic acid and the most
important molecule for life on the planet