water Flashcards
why is water a dipole
the angle of the bonds creates a negative and positively charged end due to hydrogen and oxygen being slightly charged
why do water molecules have hydrogen bonds between them
to create a continuous molecule
why is water a perfect molecule
polar solvent
thermal properties
surface tension
incompressibility
maximum density at 4 degrees celsius
what is polar solvency important
because water is a dipole and FORMS HYDROGEN BONDS , polar substances eg ions are soluble in water and can be transported around the body and chemical reactions can also occur in the water
what substances are transported by water in the blood
gases , polar molecules ( ions and amino acids ) , inorganic ions ( eg potassium )
how is surface tension created
- water molecules are polar
- water molecules are more cohesive to each other than adhesive to air molecules
- therefore the is a net inward surface force
- this creates surface tension
why is surface tension important
-so water can travel against gravity in the xylem
- so some organisms eg pondskaters can move on the surface of the water
what thermal properties does water have
it has a high specific heat capacity - long time to heat up and cool down
- it takes a lot of energy to break the hydrogen bonds and separate the water molecules
why are the thermal properties of water important to life
so the temperature of bodies of water stay relatively similar so marine life can survive
- also keeps a similar body temp so enzymes don’t denature
why is water incompressible
the bipolarity of water means that molecules repel each other and no more pressure can compress it
why is it important that water is incompressible
for hydraulic mechanisms in living organisms such as blood transport
why does water have a maximum density
water is at its highest density at 4 degrees
when water cools further , the molecules of water become more widespread ( less dense )
this is why ice floats
why is maximum water density important for life
ice can form an insulate area which can stop the water underneath from freezing
also it melts quicker on the top so marine animals can survive in freezing conditions
examples of monosaccharides
HEXOSE =glucose , fructose , galactose
PENTOSE = ribose
properties of monosaccharides
sweet
soluble in water
