The roles of water

all you need to know about the roles of water including the importance and how they happen.

HideShow resource information
Preview of The roles of water

First 85 words of the document:

1) A solvent
Importance: many biochemical reactions
occur in water. When a chemical dissolves in
water it is free to move around and react
with other chemicals.
How: water is dipolar so it attracts other
charged particles e.g. ions like Na+, K+, Cl- or
molecules which contain charged particles
e.g. glucose.
2) A metabolite
Importance: water is needed in life
sustaining reactions like photosynthesis. It is
also formed during other reactions.

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

How: water breaks down larger molecules
(hydrolysis) e.g.
glycogen glucose.
Reactions making bigger molecules
evolve water e.g.
glucose + glucose maltose + H2O
3) A transport medium
Importance: water dissolves and carries
mineral salts in xylem, it also carries sucrose
and amino acids in phloem. Plasma in our
blood vessels carries many things.
How: H-bonds hold water molecules
together (cohesion) This prevents air
bubbles from forming in xylem, phloem and
blood plasma.…read more

Page 3

Preview of page 3

Here's a taster:

As a thermos
Importance: most cells only survive within
narrow temperature limits, otherwise their
enzymes can't work well. Many organisms
have water as their habitat for feeding,
breeding, baring young and migrating.
How: the `movement' of water molecules is
restricted because of the H-bonds between
them. A lot of energy is needed to raise the
temperature of water by 1 c for 1Kg this is
because water has a high specific heat
capacity.…read more

Page 4

Preview of page 4

Here's a taster:

As an insulator
Importance: ice floats on water's surface,
insulating the water below and allowing
nutrient cycling. Fish can survive the winter!
How: water is most dense at 4 c so frozen
water (ice) will rise up.
6) As a surface for insects to walk on
Importance: some insects can walk on
How: H-bonds between H2O molecules allow
enough cohesion; `surface tension' for pond
skaters and Jesus bugs to walk.…read more


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all resources »