Water Flashcards
(11 cards)
What is the structure and bonding in Water?
- Water is a convalent compound made of 2 hydrogens and 1 oxygen
- Oxygen has a slight negative charge and hydrogen atoms have a slight positive charge. this means it is dipolar.
- Hydrogen bonds form between water molecules due to the opposite charges
Explain the property of high specific heat capacity.
Water is a polar molecule, and so H bonds form between molecules.
This property means water absorbs relatively large amounts of heat before its temperature changes.
Why is specific heat capacity in water important for biology?
Water acts as a buffer against temperature fluctuations, which is important for 2 reasons:
1)Temperature of bodies of water e.g. lakes are more stable than the surrounding air temperatures, so it is a good habitat.
2) Helps organisms maintain a constant internal body temperature, since they are mostly made of water.
Explain the property of large latent heat of vaporisation.
Water is a polar molecule, and so H bonds form between molecules.
This property means water absorbs large amounts of heat before it evaporates (when H bonds break)
Why is large latent heat of vaporisation important in biology.
Evaporation of just a small amount of water is an effective means of cooling (temperature regulation) - helping organisms to maintain a constant body temperature.
Explain the property of cohesion between water molecules.
Water is a polar molecule, and so H bonds form between molecules.
This property causes water molecules to stick together.
Why is cohesion between water molecules important in biology?
Column of water doesn’t break when pulled up a narrow tube e.g. xylem during transpiration.
Produces surface tension at an air water surface e.g. so pond skaters can walk on water.
What does water being a metabolite mean for it?
Water is reactive.
Explain the importance of the property of water being a metabolite.
Condensation releases H2O and forms a chemical bond.
Hydrolysis requires H2O to break a bond, e.g. amino acids joined by condensation reactions to form polypeptides
Explain the property of water being a universal solvent.
water is a polar molecule, casing the positive end of the water molecule to be attracted to a negative ion and the negative end connects to a positive ion.
Ions and polar molecules can be dissolved
What is the importance of water being a universal solvent?
Water can dissolve other substances (oxygen, urea, inorganic ions, enzymes)
Most metabolic reactions take place in solutions, which is good as the random movement of molecules increases, so the rate of successful collisions increases.
