Water and ions Flashcards
Ion
Charged particle formed by the loss of gain of one or more electrons
What are the most common elements in living organisms?
Hydrogen
Carbon
Oxygen
Nitrogen
Role of Mg2+
Important component in chlorophyll= green pigment in plants which absorbs light
Animals= bones
What condition means plants don’t have magnesium so can’t make chlorophyll?
Chlorosis
Role of Fe2+
Constituent of haemoglobin which transports oxygen in red blood cells
Role of Po43-(phosphate)
Makes nucleotides/ component of nucleic acids like RNA, DNA and ATP in plants and animals
Constituent of phospholipids
Role of Ca2+
Strengthens bones, teeth and tissues in animals and plant cell walls
Structural
Why is water essential
All reactions of life rely on water and key elements are found dissolved in aqueous solutions
65-95% of the mass of many plants and animals
Dipole
A polar molecule with a positive and negative charge separated by a small distance
Hydrogen bond
Weak attractive force between the partial positive charge of a hydrogen atom of one molecule and the partial negative charge on another atom, normally oxygen or nitrogen
Why is the ability to form hydrogen bonds good?
The large number of them makes molecules difficult to separate and gives A wide range of physical properties
Water surface tension
Cohesion at the surface produces this
At ordinary temp water has the highest besides mercury
Insects like pond skaters are supported
Cohesion
Multiple hydrogen bonds stick together in a lattice
This allows water to move up in xylem vessels and for habitats to be built
Water as a solvent
Called the “universal solvent”
Because of the fact it is a dipole they attract other polar molecules like glucose for chemical reactions
Animals: kidney filtering
Plants: soluble nutrients
Specific heat capacity
Large amount of heat energy is needed to raise its temperature
KE is reduced so temp change is stopped
prevents large fluctuations so habitats are stable
