Water Flashcards
(34 cards)
What % of a cell content is water ?
80%
Why is water important?
Metabolite. Solvent. Helps with temp control. High latent heat of vaporisation. High specific heat capacity. Very cohesive.
Why is water a metabolite?
It’s important metabolic reactions.
Condensation/ hydrolysis.
Why is water a solvent?
Substances dissolve in it and most metabolic reactors occur in solution.
How does water help with water temperature?
High latent heat of vaporisation.
High specific heat capacity.
Water molecules are very cohesive, why is this good?
Helps water transport in plants.
What is the structure of water?
One atom of oxygen.
Joined to 2 atoms of hydrogen.
By shared electrons.
Where is the shared negative hydrogen electron pulled towards?
Oxygen atom.
Meaning other side of each hydrogen atom is left with slight positive charge.
What charge do the unshared electrons have on oxygen molecule ?
Slight negative charge
So why is water a polar molecule ?
Partial negative charge on one side and partial positive charge on the other.
Are the hydrogen bonds strong or weak ?
Weak
Where are the hydrogen bonds found?
Between slightly positively charged hydrogen atom in one molecule and slightly negatively charged atom in another molecule.
Give example of metabolic reactions?
Condensation and hydrolysis reaction .
Why does a hydrolysis reaction need water ?
To break a bond.
Why does a condensation reaction need water?
It releases one as a new bond is formed.
Give example of condensation reaction.
Amino acids join together to make polypeptides
Give example of hydrolysis reaction.
Energy from ATP released is through hydrolysis reaction.
What does it mean if a substance is ionic?
Made from one positively charged atom and one negatively charged atom.
Give an example of an ionic molecule ?
Salt
Positive sodium ion
Negative chloride ion
How will the ions get surrounded by water ?
As the slightly positive charged end of water molecule will be attracted to negative ion.
Negative ion will be attracted to positive ion.
Dissolve
So how is a water polarity good for humans?
They can take up substances like mineral ions dissolved in water and they can be transported around the organisms Body.
What is a metabolic reaction?
Chemical reaction happening inside a living organism.
Metabolite is substance involved in the reaction.
When will water evaporate?
When the hydrogen bonds holding water molecules together are broken.
Allows water molecules on surface to escape into air as gas.
Why is it difficult for water to evaporate?
As it takes a lot of energy to break hydrogen bonds between water molecules.
High latent heat of vaporisation .
