Water Flashcards
What type of molecule is water?
Polar
What makes water a polar molecule?
Uneven distribution of charge within the molecule
What makes the charge in a water molecule an uneven distribution?
Hydrogen atoms are more positive than the oxygen atom.
What does water being a polar molecule mean for the molecule?
One end of the molecule is more positive than the other
In metabolic reactions what is water?
Metabolite
What are metabolites used in for chemical bonds?
Forming and breaking the bonds
What is water in which many metabolic reactions occur?
Solvent
What does it mean for water that it has a high specific heat capacity?
A lot of energy is required to warm water
What is a benefit of water having a high specific capacity? What does it act as? What is it called nd what does it support?
Minimising temperature fluctuations in living things therefore acting as a temperature buffer?
What does it mean that water has a relatively large/high latent het of vaporisation?
Evaporation of water provides a cooling effect with little water loss.
What does strong cohesion between molecules enables and why?
Effective transport of water in tube-like transport cells as the strong cohesion supports columns of water.
What is the result of strong cohesion?
Surface tension at the water ir boundary is high.
What is the maximum density of water at?
4 degrees.
What does it mean for the density of water?
Ice is less dense than water and floats on top creating an insulating layer.
What does the 4 degree density of water mean in terms of survival?
Increases the chance of survival of organisms in large bodies of water as it prevents them from freezing.
Why does water provide good support?
Incomprensible
What do water molecules consist of and how are they bonded?
Two hydrogen atoms covalently bonded to an oxygen atom.
Which atom in water attracts electrons more strongly and what charge does it make it?
Oxygen. Partially negative.
What charge does the hydrogen particles have?
Partially positive
What re hydrogen bonds?
Attractions between positive hydrogen end of one water molecule and the negative oxygen end of another.
How strong are hydrogen bonds in comparison to others?
Relatively strong compres to other types of intermolecular forces but still weaker than covalent bonds.
What is the range of water on liquid form?
0-100
Why does water remain liquid over a large temperature range?
Has high melting and boiling points.
What can water do given that it is liquid at room temperature?
Provide habitats for living organisms.
Form a major component of tissues in living organisms.
Provide a reaction medium for chemical reactions.
Be an effective transport medium eg: in blood and vascular tissue.
Why does water have high melting and boiling points?
Strong forces of attraction between the hydrogen bonds.
Why do substances with weak forces of attraction between the molecules melt and boil at much lower temperatures?
A lot less energy is needed to overcome the forces of attraction between the molecules, knowing the molecules to move more and change from a solid to a liquid or liquid to a gas.
What is meant by hydrophilic?
Water loving.
Give an example of a hydrophilic molecules.
Charged or polar molecules.
Eg: salts, sugars, amino acids.
What is meant by hydrophobic molecules?
Water hating.
Give an example of hydrophobic molecules.
Uncharged or non polar molecules.
Eg: lipids.
Why can’t water dissolve no polar molecules?
No charge for the water to attract to.
What is cohesion?
Hydrogen bonds cause water molecules to stick together.
What is adhesion?
Water molecules attracted to the wall of narrow xylem vessels for example.
What is surface tension?
Molecules at the surface are only attracted to neighbouring molecules below and to the sides but not abound creating an imbalance.
Surface molecules are only attracted downwards and sideways due to cohesive forces , net inward force.
What is waters participation in in a hydrolysis reaction?
Break chemical bond between 2 molecules and involves the use of a water molecule.
What is waters participation in in a hydrolysis reaction?
Break chemical bond between 2 molecules and involves the use of a water molecule.
What is waters participation in condensation reactions?
Joins 2 molecules together with the formation of a chemical bond and involves the elimination of a molecule of water.
