Water/osmosis
Cue Notes
Water Glossary Adhesion: The attraction of one kind of molecule to a different kind of molecule.
Cohesion: The attraction between the same type of molecule.
Density: How closely packed together things are. Mass/volume= density.
Dipole: The uneven sharing/distribution of electrons between 2 atoms engaging in a
covalent bond. This causes the molecule to have a positive and negative pole.
Latent heat of vaporisation: The energy needed to change a substances state from a
liquidgas or vice versa.
Specific heat capacity: The energy need to raise the temperature of 1kg of a
substance by 1^c.
Hydrogen bond: The attraction created between a partially electropositive hydrogen
atom and a partially electronegative oxygen atom.
Solvent: a substance that can dissolve other molecules or compounds.
Solute: a substance that can be dissolved by a solvent to create a solution.
Surface tension: A property of a liquid that allows it to resist an external force, due to
the cohesive nature of its molecules.
Where are the poles and how do
they from hydrogen bonds?
As water molecules are dipoles, they attract charged particles, like ions. These then dissolve in
How does the polarity of water the water, so chemical reactions take place in the solution.
allow it to dissolve compounds?
The properties of dipole-natured 1. Acts as a transport medium: plasma transports dissolved substances in animals.
water required to support life: Water transports minerals in the xylem and sucrose and amino acids in the phloem.
2. A metabolite: used as a reactant in many biochemical reactions (e.g. In
photosynthesis and hydrolysis)
3. High Specific heat capacity: water can absorb large amounts of energy and only raise
the temperature a little bit, prevents large fluctuations in water temperature and
allows metabolic functions to work efficiently.
4. High latent heat of vaporisation: A lot of heat is needed to change the state of water
from a liquid to a vapor, useful for temperature control (heat is used to vaporise
water from sweat from the skin- to cool us down)
5. Cohesion: water molecules attract to each other forming hydrogen bonds. As there
are many, they stick together in a lattice structure. Used to draw water up the xylem.
6. High surface tension: cohesion between water molecules at the surface creates
uyUseful for insects on a pond as they can be supported.
surface tension.
7. High density: provides support and buoyancy for aquatic organisms. It has a
maximum density at 4^C, so ice is less dense than water so floats. Ice is a good
insulator and prevents the whole body of water from freezing- organisms survive
beneath.
8. Transparent: lets aquatic plants to synthesise effectively.
Hypotonic solution: When the extracellular fluid is less concentrated than the cell;
Osmosis Glossary water moves into the cell and causes it to become turgid.
Hypertonic solution: When the extracellular fluid is more concentrated than the cell;
water moves out of the cell and causes it to become shrivelled.
Isotonic solution: When the solution is the same concentration as the cell so there
will be no water movement.
Water potential: The tendency for water to move into a system; water moves from a
solution with a higher water potential to one with a lower water potential. It is
decreased by the addition of a solute and is 0 in distilled/pure water (always
negative).
Cue Notes
Water Glossary Adhesion: The attraction of one kind of molecule to a different kind of molecule.
Cohesion: The attraction between the same type of molecule.
Density: How closely packed together things are. Mass/volume= density.
Dipole: The uneven sharing/distribution of electrons between 2 atoms engaging in a
covalent bond. This causes the molecule to have a positive and negative pole.
Latent heat of vaporisation: The energy needed to change a substances state from a
liquidgas or vice versa.
Specific heat capacity: The energy need to raise the temperature of 1kg of a
substance by 1^c.
Hydrogen bond: The attraction created between a partially electropositive hydrogen
atom and a partially electronegative oxygen atom.
Solvent: a substance that can dissolve other molecules or compounds.
Solute: a substance that can be dissolved by a solvent to create a solution.
Surface tension: A property of a liquid that allows it to resist an external force, due to
the cohesive nature of its molecules.
Where are the poles and how do
they from hydrogen bonds?
As water molecules are dipoles, they attract charged particles, like ions. These then dissolve in
How does the polarity of water the water, so chemical reactions take place in the solution.
allow it to dissolve compounds?
The properties of dipole-natured 1. Acts as a transport medium: plasma transports dissolved substances in animals.
water required to support life: Water transports minerals in the xylem and sucrose and amino acids in the phloem.
2. A metabolite: used as a reactant in many biochemical reactions (e.g. In
photosynthesis and hydrolysis)
3. High Specific heat capacity: water can absorb large amounts of energy and only raise
the temperature a little bit, prevents large fluctuations in water temperature and
allows metabolic functions to work efficiently.
4. High latent heat of vaporisation: A lot of heat is needed to change the state of water
from a liquid to a vapor, useful for temperature control (heat is used to vaporise
water from sweat from the skin- to cool us down)
5. Cohesion: water molecules attract to each other forming hydrogen bonds. As there
are many, they stick together in a lattice structure. Used to draw water up the xylem.
6. High surface tension: cohesion between water molecules at the surface creates
uyUseful for insects on a pond as they can be supported.
surface tension.
7. High density: provides support and buoyancy for aquatic organisms. It has a
maximum density at 4^C, so ice is less dense than water so floats. Ice is a good
insulator and prevents the whole body of water from freezing- organisms survive
beneath.
8. Transparent: lets aquatic plants to synthesise effectively.
Hypotonic solution: When the extracellular fluid is less concentrated than the cell;
Osmosis Glossary water moves into the cell and causes it to become turgid.
Hypertonic solution: When the extracellular fluid is more concentrated than the cell;
water moves out of the cell and causes it to become shrivelled.
Isotonic solution: When the solution is the same concentration as the cell so there
will be no water movement.
Water potential: The tendency for water to move into a system; water moves from a
solution with a higher water potential to one with a lower water potential. It is
decreased by the addition of a solute and is 0 in distilled/pure water (always
negative).
