1.1 Biological molecules

Question 1

there are many inorganic ions biologically important ones include:

Answer 1

magnesium- major part of chlorophyll in leaves
iron- metal ion at centre of haemoglobin
phosphate- found in plasma membrane (cell membrane), nucleic acids (DNA) and ATP
calcium- a constituent of bones and teeth

Question 2

what are macro and micronutrients

Answer 2

-macronutrients are needed in small amounts = magnesium, iron, phosphate
-micronutrients are needed in even smaller amounts = copper and zinc

Question 3

structure of water

Answer 3

-makes up 70% of body mass
-made of 2 hydrogen + 1 oxygen
-each water has a partially positive (hydrogen) and partially negative (oxygen) end = POLAR MOLECULE
-joins together by attractive forces
-positively charged atoms (hydrogen) are attracted to negatively charged atoms (oxygen) on another molecule this attraction = HYDROGEN BONDING

Question 4

properties of water

Answer 4

• very good solvent for ionic substances e.g salt
• high specific heat= large amount of energy to cause small rise in temp important because its easier to maintain constant internal environment where enzyme controlled reactions occur
  -high latent heat = lots of energy needed to change from liquid vapour, important in temp control + sweating
• high maximum density at 4 degrees = warmest at bottom of lake for survival of organisms in winter
  -highest surface tension= surface film of standing water supports aquatic insects