Water

Question 1

What is water made of?

Answer 1

Hydrogen and oxygen

Question 2

State 5 properties of water

Answer 2

Reactive
High specific heat capacity
High latent heat of fusion
Incompressible
High cohesion

Question 3

List 5 biological uses of water

Answer 3

Raw material for photosynthesis
Solvent within cells
Turgidity in plant cells
Habitat

Question 4

Explain what dipole means

Answer 4

Dipole means a side of the molecule is slightly positive and another side slightly negative

Question 5

Define polarity

Answer 5

An uneven charge distribution within a molecule

Question 6

Define biochemistry

Answer 6

Study of the activities in living cells at the molecular level

Question 7

Importance of carbon

Answer 7

Found in all organic molecules
Carbon forms strong covalent bonds
It can join to each other forming chains or rings

Question 8

Describe the solvent properties of water

Answer 8

Water is called the universal solvent because it can dissolve many substances, especially polar substances and ionic substances. The ions and polar groups are surrounded by water molecules which separate them from each other.

This allows for the transport of nutrients vital to life in organisms

Question 9

Describe the density and freezing properties of water

Answer 9

Water molecules in ice are less dense than liquid water. Water freezes from the top down and ice floats.

Ice insulates the water below it, thus increasing the life span of the aquatic organisms

Question 10

Describe the high heat capacity of water

Answer 10

A large increase in heat energy leads to a small rise in temperature. This occurs because most of the energy is used to break hydrogen bonds, which restrict molecule movement.

Temperature changes are minimized as a result. Bodies of water maintain temperatures through the seasons for the aquatic organisms

Question 11

Describe the high heat of vaporization of water

Answer 11

Much heat energy is needed to change water to water vapor
Water’s high heat conductivity makes possible the even distribution of heat through the body

Evaporation of sweat causes the body to cool
Leaves remain cool in the heat because they lose minimal water

Question 12

Describe the high heat of fusion of water

Answer 12

Water can hold a lot of heat energy before it changes temperatures and states
These properties are great for aquatic organisms

They ensure that water will shelter organisms from drastic temperature changes and provide a stable environment, even if the air temperature changes a lot

Question 13

Describe the high surface tension of water

Answer 13

Hydrogen bonds hold water molecules together
Surface tension exists between the molecules because of the cohesive nature

Cohesion- water molecules stick together due to H+ bonds between them. The molecules at the surface come together, producing a strong layer as they’re pulled downward by the attraction of other molecules under them.

Adhesion- water molecules stick to other substances
Advantage- “capillary action” ; water moves from the roots to leaves ; water moves through the capillaries in our body