Water

Question 1

What is the importance of water?

Answer 1

• water is a metabolite which is a important part in metabolic reactions (condensation and hydrolysis)
• water is a solvent which means some substances dissolve in it most reactions take place in solution.
• water helps with temperature control because it has a high latent heat or vaporisation and high specific heat capacity
• water molecules are very cohesive which helps water transport in plants

Question 2

What is the structure of water?

Answer 2

Water is made up two hydrogen atoms and one oxygen atom. Water is overall neutral but the hydrogen has a positively charged side and oxygen has a negatively charged side. This is why we call water dipolar

Question 3

What bond is between hydrogen and oxygen ?

Answer 3

Covalent bonds

Question 4

How is water a good solvent?

Answer 4

Water is polar the slightly positively charged end of a water will be attracted to the negative ion (vice Versa). The ions will be surrounded by the water molecules which means they’ll dissolve. This means living organisms can take up useful substances dissolve in water and these dissolved substances can be transported around the organisms body

Question 5

Why is water having a high latent heat of vaporisation important?

Answer 5

Water evaporates when the hydrogen bonds holding water molecules together are broken. this allows the water molecules on the surface of the water to escape into the air as a gas. It takes a lot of energy to break the hydrogen bonds.
This is useful for living organisms because it means they can use water loss thorough evaporation to cool down without using too much water.

Question 6

Specific heat capacity

Answer 6

High
It’s the energy required to increase 1kg of water 1°c
Makes water a good temperature buffer
Enzymes are protected against denaturing
Cytoplasm buffers

Question 7

Cohesion

Answer 7

Water is cohesive which means the molecules stick to each other.
This is useful because it allows a continuous column of water to move in xylem in plants.
Cohesion leads to surface tension which allows organisms to escape from predators.
String cohesion helps water to flow making it great for transporting substances

Question 8

How are the hydrogen bonds like in ice and liquid?

Answer 8

Ice - hydrogen bonds are stable
Liquid- hydrogen bonds constantly break and reform

Question 9

Surface tension

Answer 9

Water has a high tension when it comes into contact with air. This is the reason why sweat forms droplets, which evaporate from the skin to cool an organism down.
It’s also the reason why pond skaters can walk on the surface of the pond

Question 10

What is surface tension?

Answer 10

Surface tension is the tendency of fluid surfaces to shrink into the minimum surface area possible