Water Flashcards
What is a water molecule?
Dipole
Meaning of dipole:
-Positively charged hydrogen end and a negatively charged oxygen end meaning no overall charge
Meaning of polar:
-separated charges
Hydrogen bons
-weak, but when large amounts are present in water it makes it difficult to separate
Solvent
-attracts charged particles like glucose so reactions happen in the solution
-transport medium in animals, the plasma transports dissolved substances
-in plants it transports minerals in xylem and sucrose+ amino acids in the phloem
Metabolite
-used in many biochemical reactions
-Hydrolysis and condensation
High specific heat capacity
-large amounts of heat energy needed to raise the temp
-hydrogen bonds restrict movement between molecules
-prevents large fluctuations in water temp which is important for keeping aquatic habitats stable
-stops organisms having to adapt to extreme temps
-enzymes can work efficiently
High heat capacity of vaporisation
-lot of energy is needed to change liquid to a vapour
-temperature control is used to vaporise water from sweat on the skin or leaf’s surface
-water evaporates-> body cools
Cohesion
-h2o molecules attract each other and form hydrogen bonds, many stick together in a lattice
-allows columns of water to be drawn up the xylem
High surface tension
-cohesion at the surface produces surface tension
-at normal temps water has the highest surface tension of any liquid
-pond skater is supported on the surface
Density
-max density at 4 degrees
-provides support and buoyancy for aquatic life
-ice is less dense than water because the hydrogen bonds hold the molecules further apart
-good insulator and prevents large amounts of water freezing and losing heat
Transparency of water is good because?
-allows light to reach the aquatic plants so that they can photosynthesise
