2.4: Water Flashcards
% of water in cells contents
80%
Metabolite
A substance involved in a metabolic reaction
Solvent
Some substances dissolve in it
Where do most metabolic reactions occur
in solution
Why does water help with temperature control
is has a high latent heat and high specific heat capacity
Water molecules stick together
very cohesive
How do water molecules help water transport in plants
because they are very cohesive
Charges in water molecule
slight + charge on other side on each H atom
slight - charge on O atom
(shared negative hydrogen electrons are pulled towards the oxygen atom)
Charges in water molecule makes it
a polar molecule
Hydrogen bonding in water
The slightly negative O atoms attract the slightly positive hydrogen atoms of other water molecules = hydrogen bonding
Water is an important metabolite because
molecule of water required in hydrolysis (to break a bond)
molecule of water released in condensation (new bond formed)
Why does water have a high latent heat of vaporisation
It takes a lot of energy to break the hydrogen bonds between water molecules
(a lot of energy is used up when water evaporates (vaporises))
Why is a high latent heat of vaporisation of water useful in living organisms
use water loss throigh evaporation to cool down without losing too much water
eg: sweat in humans
How can water buffer changes in temp
hydrogen bonds between water molecules absorb a lot of energy
so water has a high specific heat capacity (takes a lot of energy to heat up)
Latent heat of vaporisation
The energy used up when a substance evaporates
The energy required to evaporate 1g of water
