Download notes 2.1

HOW CELLS FUNCTION
ALL CELLS NEED ENERGY AND
MATERIALS FOR LIFE
PROCESSES
CHEMICAL REACTIONS
TAKE PLACE INSIDE CELLS
• ALL CELLS ARE MADE OF THE SAME
ELEMENTS
– All matter in the universe can be broken down into
elements (about 100 different ones found on Earth)
– 25 are needed for life; 6 make up 99% of human body
– Chemical Reactions make/brake bonds between atoms
to make different molecules
– ENERGY is needed to make bonds & is released
when bonds are broken
• LARGE MOLECULES SUPPORT CELL
FUNCTION (carbohydrates, lipids, proteins &
nucleic acids)
• ABOUT 2/3 OF EVERY CELL IS WATER
CARBOHYDRATES
• Provides cell with
ENERGY
• Simple carbs are
SUGARS which are
broken down in cell to
release energy.
• Complex carbs are
STARCH (sugars
linked & stored
together) and
CELLULOSE (nondigestible in cell
walls).
LIPIDS
• Are FATS, OILS, &
WAXES, found in
living things.
• Can store lots of
ENERGY and used
for structural support.
• Made of glycerol &
fatty acids; doesn’t
mix with water.
PROTEINS
-Made of amino acids
-Get amino acids from
eggs, meat, beans &
dairy
-Used to build & repair;
make enzymes for
chemical reactions,
help blood fight
infections & carry
oxygen
NUCLEIC ACIDS
• Are molecules that hold
instructions for the
maintenance, growth, &
reproduction of a cell.
• 2 Types: DNA (holds
information on how to
make the body’s proteins)
& RNA (copies data from
DNA in nucleus and takes
to cytoplasm so amino
acids can link into protein)
• Made of nucleotides
ABOUT 2/3 OF EVERY CELL
IS WATER
• All CHEMICAL REACTIONS inside a
cell takes place in WATER.
• Water is made of H2O; 2 hydrogen atoms
and one oxygen atom
• Water is found both inside & outside of a
cell; the cell membrane’s lipid layer
separates the 2 environments of water
(inside & outside of the cell) . The water
hating tails in the lipids repel the water
while the head clings to water.