Download 3.1-Chemical Elements of Water

3.1-Chemical Elements of Water
• 3.1.1-State that the
most frequently
occurring chemical
elements in living
things are carbon,
hydrogen, oxygen,
and nitrogen.
• 3.1.2-State that a
variety of other
elements are needed
by living organisms,
including sulfur,
calcium, phosphorus,
iron and sodium.
3.1.3-State one role for each of the
elements mentioned in 3.1.2.
– Nitrogen is part of amine
groups in amino acids, and
thus proteins
– Calcium is needed to make
the mineral that
strengthens bones and
teeth
– Phosphorus is part of
phosphate groups in DNA
and ATP
– Iron is needed to make
hemoglobin and thus carry
oxygen to the blood
– Sodium is used in neurons
for the transmission of
nerve impulses
Hemoglobin, including iron, is the material that
makes up red blood cells, above.
– Sulfur, found in the hair, nails
and skin, assists the immune
system
3.1.4-Draw and label a diagram showing the
structure of water molecules to show their
polarity and hydrogen bond formation
Hydrogen bond
Oxygen
pole is
slightly
negative
O
H
I
I
V
H -----------------
H
O
H
Hydrogen
pole is
slightly
positive
3.1.5-Outline the thermal, cohesive,
and solvent properties of water
•Thermal (Campbell book pg.43)~ Water has a large heat
capacity because of the hydrogen bonds that form
between its molecules. It takes lots of energy to break
these bonds. Water also has high boiling and freezing
points. Additionally, water can evaporate at temperatures
below its boiling point, taking the required heat energy to
break the hydrogen bonds from the liquid water, which
gives it a cooling effect.
•Cohesive (Campbell book pg.42)~ Water molecules stick
to each other because of the hydrogen bonds that form
between them.
•Solvent (Campbell book pg.45)~ Many different
substances can dissolve in water because of its polarity.
3.1.6-Explain the relationship between the properties of
water and its uses in living organisms as a coolant, medium
for metabolic reactions, and transport medium.
• Coolant~ Evaporation of water
from plant leaves
(transpiration) and from human
skin (sweat) has cooling
effects
• Medium for metabolic
reactions~ cohesive properties
of water allow strong pulling
forces to be exerted to suck
columns of water to the tops of
trees without breaking.
• Transport~ The solvent
properties of water allow many
substances to be carried
dissolved in water in the blood
of animals and the sap of
trees.
The properties of water allow water to
enter, pass through, and exit a plant.
Key Terms (pg.41-46)
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polar molecule
cohesion
adhesion
surface tension
specific heat
solution
solvent
solute
aqueous solution
hydrophilic
hydrophobic