Water And Its Functions

Question 1

What is water made of?

Answer 1

Two hydrogen atoms and one oxygen atom.

Question 2

What charge does a water molecule have?

Answer 2

No overall charge.

Question 3

What charge does the oxygen atom have?

Answer 3

A slight negative charge.

Question 4

What charge to the hydrogen atoms have?

Answer 4

A slight positive charge.

Question 5

What is a water molecule described as and why?

Answer 5

Dipolar, as it contains both positive and negative poles.

Question 6

What do different poles do?

Answer 6

Attract.

Question 7

What is the positive pole in a water molecule attracted to?

Answer 7

The negative pole of another water molecule.

Question 8

What are the attractive forces between the charged poles?

Answer 8

Hydrogen bonds.

Question 9

What feature do hydrogen bonds have?

Answer 9

They are weak.

Question 10

What do hydrogen bonds together form?

Answer 10

Important forces that cause water molecules to stick together, giving water it’s unusual properties.

Question 11

What does it mean for water molecules sticking together?

Answer 11

It takes more energy (heat) to separate them than if they did not bond to one another.

Question 12

What does it mean if water takes lots of energy to separate?

Answer 12

It has a high boiling point.

Question 13

What would water be without hydrogen bonding?

Answer 13

A gas (water vapour).

Question 14

Why does water have a high specific heat capacity?

Answer 14

As it takes more energy to heat a given mass of water.

Question 15

What does water do as it has a high specific heat capacity?

Answer 15

It acts as a buffer against sudden temperature variations.

Question 16

What’s a benefit of water acting as a buffer against temperature variations?

Answer 16

It makes the aquatic environment a temperature-stable one as well as it buffers organisms against sudden temp changes.

Question 17

What does hydrogen bonding between water molecules also mean?

Answer 17

That is requires a lot of energy to evaporate 1 gram of water.

Question 18

What is the energy needed to evaporate one gram of water called?

Answer 18

Latent heat of vaporisation.

Question 19

What is an effective means of cooling and how?

Answer 19

Evaporation of water such as sweat, as body heat is used to evaporate the water.

Question 20

What is cohesion?

Answer 20

The tendency of molecules to stick together.

Question 21

What does water have related with its hydrogen bonding?

Answer 21

Large cohesive forces.

Question 22

What does waters large cohesive forces allow?

Answer 22

It to be pulled up through a tube such as a xylem vessel in plants.

Question 23

What happens when water molecules meet air?

Answer 23

They tend to be pulled back into the body of water rather than escaping from it.

Question 24

What is surface tension?

Answer 24

Where the waters surface acts like a skin.

Question 25

What force is surface tension?

Answer 25

Water molecules being pulled back into the body of water.

Question 26

How is water used in metabolism?

Answer 26

To break down many complex molecules by hydrolysis, and be produced in condensation reactions.

Question 27

What do chemical reactions take place in?

Answer 27

Aqueous mediums.

Question 28

What is water a raw material for?

Answer 28

Photosynthesis.

Question 29

What does water readily do?

Answer 29

Dissolves other substances.

Question 30

What substances can water readily dissolve?

Answer 30

Gases such as oxygen and carbon dioxide, wastes such as ammonia and urea, inorganic ions and small hydrophilic molecules such as amino acids, monosaccharides and ATP, and enzymes whose reactions take place in solution.

Question 31

What does evaporation in organisms allow?

Answer 31

Them to control their temperature.

Question 32

What can’t water easily do?

Answer 32

Be compressed.

Question 33

What’s a benefit of water not being easily compressed?

Answer 33

It provides support.

Question 34

What is a benefit of water being transparent?

Answer 34

Aquatic plants can photosynthesise.

Question 35

Where are inorganic ions found?

Answer 35

In solution in the cytoplasm of cells and in body fluids of organisms.

Question 36

What does an ions specific function relate to?

Answer 36

It’s properties.

Question 37

What do iron ions in haemoglobin do?

Answer 37

Play a role in the transport of oxygen.

Question 38

What are hydrogen ion’s important in?

Answer 38

Determining the pH of solutions and the functioning of enzymes.