Water 1B

Question 1

Functions of water

Answer 1

1. Water is a metabolite in loads of important metabolic reactions including condensation reactions and hydrolysis reactions
2. Water is a good solvent which means that some substances can dissolve in it
3. Water helps with temperature control as it has a high latent heat of vaporisation and a high specific heat capacity
4. Water is very cohesive which helps water transport in plants and transport in other molecules

Question 2

Structure of water

Answer 2

(H2O) - covalent bonding the shared negative hydrogen electrons are pulled towards the oxygen atoms the other side of each hydrogen atom is left with a slight positive charge . The unshared negative electrons on the oxygen atom give it a slight negative charge.
This makes water a polar molecule.
The attraction between the oxygen and hydrogen atoms is called hydrogen bonding

Question 3

What does it mean by water is a good metabolite

Answer 3

Water is involved in making and breaking bonds in chemical reactions

Question 4

What does it mean by water has a high latent heat of vaporisation

Answer 4

It takes a lot of energy (heat) to break the hydrogen bonds between water molecules so water has a high latent heat of vaporisation a lot of energy is used up when water vaporises. This is useful because it helps organisms to cool down without using too much water

Question 5

How does water buffer changes in temperature

Answer 5

The hydrogen bonds between water molecules can absorb a lot of energy. So water has a high specific heat capacity a lot of energy is required to raise its temperature. This is useful for living organisms because water doesn’t experience rapid temperature changes so aquatic animals are able to maintain a stable internal environment

Question 6

What makes water a good solvent

Answer 6

made from one positively charged ion and one negatively charged ion because water is polar the positive end of a water molecule is attracted to the negative ion and the negative end will be attracted to the positive ion. This means the ions will be totally surrounded by water- they’ll dissolve

Question 7

What causes the strong cohesion between water molecules

Answer 7

Cohesion is the attraction between molecules of the same type. Water molecules are very cohesive as they’re polar.
Strong cohesion helps water flow making it great for transporting substances
Strong cohesion also means that water has a high surface tension when it comes into contact with air. This is why sweat forms droplets, which evaporate from the skin to cool an organism down and is also why pond skaters can “walk” on water