1 Biological Molecules- Water Flashcards
What is water a major component of?
Cells in the body
What is the structure of water (H2O)?
-One oxygen and two hydrogen atoms
-Polar molecule (oxygen has a slightly negative charge and hydrogen’s have a slightly positive charge)
-The hydrogen atom on one molecule is attracted to the oxygen atom on another molecule due to their polarity (opposite charges). This is called hydrogen bonding
What are the 5 special properties of water?
-Metabolic importance
-High heat capacity
-Heat of vaporisation
-Cohesive properties
-Useful as a solvent
Why is water a good solvent?
Ions and polar molecules can easily dissolve in it (water is polar itself)
What is specific latent heat of vaporisation and why does water having a high measure of this helpful?
The amount of energy needed to change 1 kg of a liquid substance to a gas
As liquid water heats up, hydrogen bonding makes it difficult to separate the water molecules from each other so a lot of energy is needed for water to evaporate- cooling the nearby environment (why sweating helps body temperature regulation)
What is cohesion and how is it useful?
The strong attraction between water molecules due to hydrogen bonding
This produces surface tension where water meets air, which is why water produces droplets when placed on a dry surface and isn’t flattened out due to gravity
Cohesion helps plants transport water from their roots to leaves (transpiration)
What is specific heat capacity and why is it helpful that water has a high measure of this?
The amount of heat 1 g of a substance must absorb/lose to change its temperature by 1.c
Water has a high amount of this (larger than sand,why land cools quicker than sea) so takes a long time to heat and cool
Water is used by warm-blooded animals to more evenly disperse heat in their bodies
Helps organisms in aquatic environments
How is water a good metabolite?
It is used/formed in many metabolic reactions, like hydrolysis and condensation (e.g. ATP)
