Water in Cells

Question 1

Water is composed of

Answer 1

atoms of hydrogen and oxygen. One atom of oxygen combines with two atoms of hydrogen by sharing electrons (covalent bonding)

Question 2

Although water as a whole is electrically neutral the sharing of the electrons is uneven between the oxygen and hydrogen atoms

why?

Answer 2

The oxygen atom attracts the electrons more strongly than the hydrogen atoms, resulting in a weak negatively charged region on the oxygen atom (δ-) and a weak positively charged region on the hydrogen atoms(δ+), this also results in the asymmetrical shape

Question 3

his separation of charge due to the electrons in the covalent bonds being unevenly shared is called a

Answer 3

dipole

Question 4

dipole. When a molecule has one end that is negatively charged and one end that is positively charged it is also a …

Answer 4

a polar molecule
Water is a polar molecule

Question 5

Hydrogen bonds form between water molecules
As a result of the

Answer 5

polarity of water hydrogen bonds form between the positive and negatively charged regions of adjacent water molecules

Question 6

Hydrogen bonds are ….., when there are few, so they are constantly breaking and reforming. However when there are …………numbers present they form a strong structure

Answer 6

weak

large

Question 7

Hydrogen bonds contribute to the many properties water molecules have that make them so important to living organisms:

water’s properties

Answer 7

An excellent solvent – many substances can dissolve in water

A relatively high specific heat capacity

A relatively high latent heat of vaporisation

Water is less dense when a solid

Water has high surface tension and cohesion

It acts as a reagent

Question 8

Water has many essential roles in living organisms due to its properties

Answer 8

The polarity of water molecules

The presence and number of hydrogen bonds between water molecules