water and inorganic ions

• what is the purpose of water

  takes part in many biochemical reactions

  provides an aqueous environment for other biochemical reactions

  transport medium for food molecules, waste and hormones

  provides turgor support in plants

  provides hydrostatic support in some animals

  resists temperature change and protects aquatic organisms from extreme temperatures
• why is water a dipolar molecule

  the H is slightly + and the O is slightly -
• what is the strength of hydrogen bonds

  very weak and are easily broken by high temperatures
• why is water an excellent solvent for ions and polar molecules

  water molecules are attracted to them, collect around and separate them
• why do non polar molecules like lipids not dissolve in water

  they get pushed together by it
• draw a water molecule, labelling the hydrogen bonds

  labels

  A) hydrogen bonds between molecules

  B) slightly negative

  C) slightly positive

  
• what is the symbol for a sodium ion

  Na+
• what does sodium do

  nerve impulse conduction and osmoregulation
• where is sodium found

  salt
• what is the symbol of a potassium ion

  K+
• what does potassium do

  nerve impulse conduction
• where is potassium found

  bananas and general foods
• what is the symbol for a magnesium ion

  Mg2+
• what does magnesium do

  enzyme activator, part of chlorophyll molecule that helps photosynthesis occur in plants
• where is magnesium found

  leafy vegetables
• what is the symbol for a calcium ion

  Ca2+
• what does calcium do

  calcium phosphate strengthens teeth and bones

  prevents blood clotting

  muscle contraction

  calcium pectate binds cell walls together in plants
• where is calcium found

  dairy products
• what is the symbol for an iron ion

  Fe2+
• what does iron do

  component of haemoglobin and cytochromes in e- transport chain, needed for chrlorophyll synthesis in plants
• where is iron found

  red meat
• what is the symbol for a chloride ion

  Cl-
• what does chloride do

  component of HCl in gastric juice and osmoregulation
• where is chloride found

  salt
• what is the symbol for a carbonate ion

  CO3^2-
• what is the symbol for a hydrogencarbonate ion

  HCO3^-
• what does carbonate and hydrogencarbonate do

  forms a buffering system which helps to maintain the pH of bodily fluids

  blood proteins such as albumin
• what is the formula of a nitrate ion

  NO3^-
• what does nitrate do

  taken into plant roots by active transport for synthesis of amino acids
• what does a lack of nitrate cause

  poor growth
• what does a lack of iron cause

  anaemia

  chlorosis in plants
• what is the symbol for a phosphate ion

  PO4^3-
• what does phosphate do

  component of ATP, DNA, RNA, NAD, NADp and phospholipids in cell membranes
• where is phosphate found

  dairy produce, meat and fish
• what are buffers

  chemicals or substances that resist changes to pH and ensure that a particular environment maintains a particular pH
• where are buffers found

  blood proteins such as albumin and tissue fluid