Biological Molecules: Water Flashcards
(16 cards)
What percentage of cells is made up of water?
80%
Why is water necessary in metabolic reactions?
Because water is a metabolite in lots of important metabolic reactions, such as condensation and hydrolysis.
Why is it useful that water is a solvent?
Some substances dissolve into water, which is useful because most metabolic reactions take place in solutions.
Water qualities of water aids in temperature control?
Some substances dissolve into water, which is useful because most metabolic reactions take place in solutions.
Water qualities of water aids in temperature control?
It has a high latent heat of vaporisation and a high specific heat capacity.
Water qualities of water aids in temperature control?
It has a high latent heat of vaporisation and a high specific heat capacity.
What water quality aids water transport in plants?
It has a high latent heat of vaporisation and a high specific heat capacity.
What water quality aids water transport in plants?
Water molecules are very cohesive, meaning they stick together which aids transport in plants and other organisms.
What is the structure of water, and how does it affect the charges of the electrons?
The structure of water is H2O, joined together by covalent bonding.
The shared electrons from the hydrogen are pulled towards the oxygen, giving that side of the hydrogen atoms a slight positive charge.
The unshared negative electrons on the oxygen atoms have a slight negative charge. This makes water a polar molecule.
What is the structure of water, and how does it affect the charges of the electrons?
The slightly negatively charged oxygen atoms attract the slightly positive charged hydrogen atoms of other water molecules, forming hydrogen bonds.
What is latent heat of vaporisation?
It takes a lot of heat energy to break the hydrogen bonds between water molecules, so water has a high latent heat of vaporisation because a lot of energy is used up when water evaporates.
Why is water having a high latent heat of vaporisation helpful for living organisms?
It means organisms can cool down by losing water by evaporation, without losing too much.
Why is water a buffer?
Water is a buffer because it can resist rapid changes in temperature.
This is because the hydrogen bonds can absorb a lot of energy, which gives water a high SHC.
Why is water being a buffer useful to organisms?
Because it means that water doesn’t experience rapid temperature change. Water is therefore a good habitat because it is relatively stable, and it means organisms don’t experience rapid temperature change from the water in our cells.
Why do ionic substances such as salt dissolve into water so easily?
Because the ions are made up of one positive atom and one negative atom, which means the positive atom is attracted to the negative oxygen, and the negative atom is attracted to the positive side.
What is water cohesion?
Water cohesion is the attraction of two water molecules.
What is adhesion?
When two different substances stick together.
Why can some insects, such as pond skaters ‘walk on water’?
Because water has a strong surface tension because of the strong cohesion between the water molecules.
