basics of molecules and inorganic ions

• what happens to electrons during covalent bonding?

  A covalent bond occurs when two atoms share a pair of electrons. The electrons used are unpaired and present in the outer shells of the atoms
• what happens to electrons during ionic bonding?

  In ionic bonds one atom of the pair donates an electron and the other receives it. This forms positive and negative ions that are held together by attraction of charges.
• If atoms contain differing numbers of electrons to protons they are known as Ions.

  If an atom has lost one or more electrons it has become positively charged.

  If an atom has gained one or more electrons it has become negatively charged
• A Cation is a positive ion and an Anion is a negative ion.

  Ions in solution are electrolytes, they have very important roles in living organisms.
• Ca2+

  Nerve impulse transmission and muscle contraction
• Na+

  Nerve impulse transmission and kidney function
• K+

  Nerve impulse transmission and stomatal opening
• OH- and H+

  Catalysis of reactions and pH determination
• NO3-

  Nitrogen supply to plants for amino acid and protein formation
• PO43*-

  Nucleic acid and ATP formation. Cell membrane formation
• HCO3-

  Maintenance of blood pH
• Cl-

  Balance positive charge of sodium and potassium ions in cells
• A Monomer is a single subunit of a polymer. A Polymer is a molecule built up of many monomers.
• match the monomers to the polymers

  Amino Acid = protein

  nucleic acid = DNA

  fatty acid and glycerol = Lipid

  sugar = carbohydrate

  
• Draw the electronic configuration of sulphur

  2.8.6
• Are amino acids an example of a monomer or a polymer?

  monomer
• Give an example of a polymer

  protein

  carbohydrates

  lipids

  DNA
• Which ion is vital for maintaining blood pH?

  HCO3-
• Is Calcium a cation or an anion? Explain why

  cation positively charge