The Chemistry of Life

Polar Molecule: A molecule with one end
having positive electrical charge and the
other end having negative electrical charge.
Water has “Polar
Covalent” bonds.
 Hydrogen Bonds:

◦ A weak attraction
between the
hydrogen of one
molecule and a
slightly negative
atom on another
molecule.
◦ External Bond

http://www.clearbiology.com/biochemistry-reviewactivity/
Color code the water molecules and hydrogen
bonds the following:
Blue = Oxygen
Red = Hydrogen
Yellow = Positive Pole
Orange = Negative Pole
Purple = Hydrogen Bonds

Working with a partner you will follow the
directions and record the observations you
make.
Cohesion & Adhesion




An attraction between substances of the
same kind.
Hydrogen bonds between water molecules.
Molecules at the surface of water are linked
together by hydrogen bonds.
Surface Tension: attraction between water
molecules due to hydrogen bonds.



An attraction between different substances.
Capillary Action: Water moves upward due to
adhesion of water to another surface.
Ex: The water in the ground moves up a
plant by being attracted to the walls of the
tube in the stem bring water from roots to
leaves.
Cohesion & Adhesion
https://www.youtube.com/watch?v=aVmU3CLxvgU
Properties of Water 4:12
https://www.youtube.com/watch?v=ynk4vJa-VaQ
Slo Mo Surface Tension 3:30
A
B
A
What is occurring in A and B? – Be prepared to explain your response.
Choices – Adhesion or Cohesion



Summarize the property – define all key
terms.
Explain how property helps to support life.
Include examples.