1. Water and the Fitness of the Environment
Chapter 3
Water and the Fitness of the Environment

2. Hydrogen bond H O H  –  +  –  +  –  +  –  + —— ——
Fig Why can the 4 outer water molecules bond with the center water molecule?
 –
Hydrogen
bond
 + H —— O
 –
 + —— H
 –
 +
Figure 3.2 Hydrogen bonds between water molecules
 –
 +

3. Adhesion Water-conducting cells Cohesion 150 µm
Fig Describe the role of adhesion and cohesion in the movement of water up a tree.
Adhesion
Water-conducting
cells
Direction
of water
movement
Cohesion
Figure 3.3 Water transport in plants
150 µm

4. Fig. 3-4 What allows the water strider to walk on water?
Figure 3.4 Walking on water

5. San Bernardino Burbank Santa Barbara 73° 100° 90° Riverside 96°
Fig How does a large body of water effect local climate?
San Bernardino
100°
Burbank
90°
Santa Barbara 73°
Riverside 96°
Los Angeles
(Airport) 75°
Santa Ana
84°
Palm Springs
106°
70s (°F)
80s
Pacific Ocean
90s
100s
Figure 3.5 The effect of a large body of water on climate
San Diego 72°
40 miles

6. Hydrogen bonds are stable Hydrogen bonds break and re-form
Fig If water did not form hydrogen bonds, what would happen to the shrimp’s environment?
Hydrogen
bond
Ice
Hydrogen bonds are stable
Figure 3.6 Ice: crystalline structure and floating barrier
Liquid water
Hydrogen bonds break and re-form

7. – – – – – – – – – – – + + + + + + + + + + Na Na Cl– Cl–
Fig What would happen if you heated this solution for a long time? – Na + + + – – + – – Na + – + +
Cl–
Cl– + – – + – + –
Figure 3.7 Table salt dissolving in water –

8. (b) Lysozyme molecule (purple) in an aqueous environment
Fig. 3-8bc What properties can make even large proteins dissolvable in water?
Figure 3.8 A water-soluble protein
(b) Lysozyme molecule (purple) in an aqueous
environment
(c) Ionic and polar regions
on the protein’s surface
attract water molecules.

9. 2H2O Hydronium ion (H3O+) Hydroxide ion (OH–)
Fig. 3-By convention, what is hydronium ion represents as? H H O O O H O H H H H H
2H2O
Hydronium
ion (H3O+)
Hydroxide
ion (OH–)

10. Fig. 3-9 What is the change in [H+] when moving from pH 4 to pH 9?
pH Scale 1
Battery acid
Gastric juice,
lemon juice 2 H+ H+ H+ H+
OH– 3
Vinegar, beer,
wine, cola
OH– H+ H+
Increasingly Acidic
[H+] > [OH–] H+ H+ 4
Acidic
solution
Tomato juice
Black coffee 5
Rainwater 6
Urine
OH–
Saliva
OH–
Neutral
[H+] = [OH–] H+ H+
OH– 7
Pure water
OH–
OH– H+
Human blood, tears H+ H+ 8
Seawater
Neutral
solution 9
Figure 3.9 The pH scale and pH values of some aqueous solutions 10
Increasingly Basic
[H+] < [OH–]
Milk of magnesia
OH–
OH– 11
OH– H+
OH–
OH–
Household ammonia
OH– H+
OH– 12
Basic
solution
Household
bleach 13
Oven cleaner 14

11. More acidic 1 2 3 Acid rain Acid rain 4 5 Normal rain 6 7 8 9 10 11 12
Fig How can acid rain affect living systems?
More
acidic 1 2 3
Acid
rain
Acid
rain 4 5
Normal
rain 6 7 8 9 10
Figure 3.10 Acid precipitation and its effects on a forest 11 12 13
More
basic 14

12. [CO32–] (µmol/kg) 40 Calcification rate (mmol CaCO3 per m2 per day) 20
Fig. 3-11b Given that the following reaction represents calcification, predict how the calcium would affect the results and explain why.
RESULTS 40
Calcification rate
(mmol CaCO3
per m2 per day) 20
Figure 3.11 What is the effect of carbonate ion concentration on coral reef calcification?
150
200
250
300
[CO32–] (µmol/kg)