Water/ monomers + polymer Flashcards
What does polar mean
Water is slightly charged because of a distribution of electrons.
Solvent
water is polar (slightly charged) so it will dissolve any
1. Charged molecules e.g. salt ions
2. Any other ‘polar’ molecules e.g. glucose, amino acids.
Therefore Water can act as a medium for biochemical reactions in cells / organelles.
TRANSPORT
dissolved biological molecules can be transported around organisms e.g. blood stream in mammals, xylem / phloem in plants. The transpiration stream in plants works as all the water molecules are hydrogen bonded to each other along the entire column.
SURFACE TENSION
water is cohesive and hydrogen bonds to other water molecules. This creates a surface tension on ponds and a habitat for some organisms e.g. pond skaters
SPECIFIC HEAT CAPACITY
liquid water will have many hydrogen bonds within it. Therefore a lot of energy is required to raise water by 1 oC and it cools slowly. Large bodies of water are thermally stable and buffer changes in temperature. This stabilises aquatic habitats.
LATENT HEAT OF VAPOURISATION
due to extensive hydrogen bonds, a small volume of water requires a lot of energy to break all of these and evaporate. Therefore a small volume of water can have a big cooling effect in mammals.
ICE
water freezes at 0oC where all molecules have 4 hydrogen bonds. This solid / ice structure is less dense than liquid water so it floats.
This can
1. Thermally insulate liquid water below
2. Provide a habitat on the surface
METABOLITE
water is a chemical USED AND PRODUCED IN CHEMICAL REACTIONS. It is used in photosynthesis to help make sugars. It is used to break biochemical bonds (HYDROLYSIS) and is released when some bonds are made (CONDENSATION)
TRANSPARENT
this enables aquatic plants to photosynthesis
MONOMERS
single, small, soluble, repeating units that can be bonded together to form a much longer chain, or polymer.
POLYMER
large, insoluble molecule (chains and / or branched) made up from many monomers
