The Properties of Water

“the liquid of life”

Water water everywhere and

not a drop to drink

Don’t go chasing waterfalls

Like a bridge over troubled water

Rain drops keep falling on my head

The fog creeps in on little cats feet

It’s Raining men!!!

I can see clearly now, the rain is gone

Water off a ducks back

Let the rain fall down and wake my dreams

If all the rain drops were lemon drops and gum drops, oh what a rain that would be

Cry m

e

a riv

er

Singing in the rain

You’re as cold as ice

Ice, Ice, baby

Smoke on

the water

Raining on Sunday

Walking on

water

Its like rain on your wedding day

I’m H

20

intolerant

Water is the essence

of wetness and

wetness is the

essence of beauty

Its raining its

pouring the old man

is snoring

Now that’s

some high

quality

H2O

Rain drops on roses..whiskers on kittens

When Chuck Norris goes swimming, he doesn’t get wet…

the water gets Chuck

Property of Water Definition and Mechanics Biological Implications

Cohesion Water molecules stick together due to H bonds

Transpiration in plants

Adhesion

Water molecules stick to other polar molecules due to H bonds

Transpiration in plants

Capillary movement

High Specific Heat

Water does not change temperature quickly due to hydrogen bonds preventing changes in molecular movement

“cooler by the lake”

Blood used as heat transport

High Heat of Vaporization

Water absorbs high quantity of heat before it turns to a gas due to hydrogen bonds

Evaporative cooling (Sweating)

Temperature stability in water

Less Density as a Solid

Ice floats because the hydrogen bonds maximize the distance between molecules

Keeps Aquatic organisms alive during the winter

High Surface Tension

Hydrogen bonds keep water molecules connected when exposed to air

Insects walk on water

Water stays together as “drops”

Solvent of Life

The polar nature of water can dissolve any polar molecule or isolate polar part on large molecules

A) Hydrophilic : Water loving (polar)

B) Hydrophobic: Water hating (non-polar)

Living things are 75% water. Most biologically active molecules are hydrophilic

03-02-WaterTransport.swf

YouTube - Jesus lizard

http://www.youtube.com/watch?v=k310d_egbFk

Real or Fake?

Lack of injury to participants brought to you by Hydrogen Bonds and the Emergent Properties of Water

1. What is pH?The measurement of the Hydrogen (or hydronium) ions found in a hydrophilic solution

2. Where do the H+ come from?A small % of water molecules dissociate into Hydronium (H3O+) and Hydroxide (OH-) ions

H030301.swf

H030302.swfHOH H+ + OH-

Water and pH

3. How is pH measured?

10 2 3 4 5 6 7 8 9 10

1112

13

14

Increasing H+(increasing Acid)

Increasing OH-(increasing Basic)

pH = -log H+

Pure water H+ = .0000001

or = 1x10-7

-log of = 71x10

-7

Therefore: The pH of pure water is 7The numbers on the pH scale are in 10X increments

4. What does pH have to do with Biology?

A) The pH of the environment can influence

biologically active molecules

1) influence chemical reactions

2) affect the interactions of hydrogen bonds3) determine the structure of proteins

5. How do living organism control pH?

a) Living organism use “buffers” to regulate pH b) Buffers work by donating or accepting H+

from the environment

1) organic “weak” acids

2) some proteins (albumin)

H2CO3

Increasing OH- HCO3 + H+

Increasing H+

Examples of buffers

Slide 2

Ice Water Steam Slide 2

Water Dissolving Ionic Molecules

Water Dissolving Large Molecules With Many Polar Functional

Groups

Slide 2