inorganic ions + water Flashcards
what is magnesium used for in animals?
allows teeth and bones to develop
what is magnesium used for in plants?
needed to synthesis chlorophyll to allow photosynthesis to occur
what is iron used for?
component in haemoglobin which carries oxygen in red blood cells
(lack of anaemia)
what is calcium used for in animals?
important structural component for bones and teeth
what is calcium used for in plants?
important structural component for cell walls
what is phosphate used for?
needed to synthesis nucleotides (e.g. RNA, DNA)
component of phospholipids in cell membranes
what are the bonds between atoms within the same water molecule?
single covalent bonds
what are the bonds between two water molecules?
hydrogen bonds
what charge are the hydrogens in water?
partially positive
what charge are the oxygens in water?
partially negative
why is water a polar molecule?
because it has separate charges due to the unequal sharing of electrons
electrons from the hydrogen atoms get pulled towards the oxygen atom
why do electrons from hydrogen get pulled towards oxygen in water?
the oxygen atom attracts electrons a little more strongly than hydrogen does
why is water a solvent?
water molecules are dipoles so they attract charged particles which dissolve in water
why is it important for water to be a solvent?
acts as a transport medium
(animals - plasma)
(plants - minerals in xylem and sucrose in phloem)
how does water have cohesion?
water molecules attract each other forming hydrogen bonds
bonds are weak but stick together in a lattice
how does water have surface tension?
molecules on the surface of water are not effected by molecules above them so pull together more strongly
why is cohesion and surface tension important for water?
so a body of an insect can be supported
to draw columns of water up xylem vessels
how does water have thermal stability?
large bodies of water have fairly
constant temperatures
how is having thermal stability important for water?
prevents large fluctuations in water temp so keeps aquatic habitats stable
what happens when water freezes?
water expands as water molecules in ice form a rigid structure so there is more space in between them (less dense)
how is freezing important for water?
ice floats on the top of water and is a good insulator for aquatic habitats
how does water have a high specific heat capacity?
large amount of heat needed to raise its temperature because the hydrogen bonds between water molecules restrict their movement
how does water have a high latent heat of vaporisation?
a lot of heat energy is needed to change it from a liquid to a vapour
why is having a high latent heat of vaporisation important for water?
important in temperature control where heat is used to vaporise water from sweat on skin or from leaf surfaces
