biology 2.3

• what elements are carbohydrates made up of?


  Carbon, Hydrogen and Oxygen (CH2O)
• what elements are lipids made up of?


  Carbon, Hydrogen and Oxygen
• what elements are proteins made up of?


  Carbon, Hydrogen, Oxygen, Nitrogen and Sulfur
• what elements are nucleic acids made up of?


  Carbon, hydrogen, oxygen, nitrogen and phosphate
• what do carbohydrates do/ what are they useful for?


  energy storage, supply and structure includes fibre
• what do proteins do/ what is protein useful for?


  structure, transport, enzymes, antibodies and most hormones
• what do lipids do/ what are lipids useful for?


  help make cell membranes, energy supply (electrical in neurones and thermal) protection, insulation, and some hormones
• what do vitamins and minerals do/ what are v+m useful for?


  used to make other molecules, act as coenzymes or enzyme activators
• what do nucleic acids do/ what are nucleic acids useful for?


  We make these using components from our diet including phosphate
• what does water do? / why is water useful?


  it's involved in many reactions, solvent for many reactions and transports chemicals around the body
• define metabolism

  Metabolism is the sum total of all the chemical reactions in an organism.
• what is a catabolic reaction?


  break large molecules into small molecules
• what is an anabolic reaction?

  build up large molecules from small ones
• all biological molecules are organic except one, which one?


  water
• what do organic molecules contain?


  carbon
• why is carbon special?


  it can join to other carbon atoms and atoms of other elements so can form large macromolecules
• what bonds can carbon form?


  can form strong bonds with other atoms -covalent bonding , can form double bonds, and can form a large number of molecules by forming rings or chains
• what is a condensation reaction?


  When biological monomers are joined together a water molecule is released
• how does a hydrolysis reaction occur?


  A covalent bond is broken and two smaller molecules are formed.
• what are hydrogen bonds like/ what are they used for?


  they are weak bonds between slightly charged parts of a molecule and they can help stabilise the structures of large polymers
• what are the monomers and polymers of carbohydrates?


  monomer = monosaccharides

  polymer = polysaccharides
• what are the monomers and polymers of proteins?


  monomer = amino acids

  polymer = polypeptides + proteins
• what are the monomers and polymers of nucleic acids?


  monomer = nucleotides

  polymer = DNA and RNA
• what is cohesion?


  water is attracted to itself (eg: moves water up the xylem of tree)
• what is adhesion?


  water is attracted to another substance (eg: walls of the xylem)
• why does water have good thermal stability?


  temperatures in large bodies of water remain fairly constant due to H bonds restricting movement therefore providing a stable environment thermally
• why is it important that water has a high latent heat of vapourisation?


  good for cooling down the body

  eg: when the sweat evaporates you cool down as it removes energy
• two examples of water being used as a solvent.


  polar molecules dissolve in it - useful as metabolic processes need chemicals to react in a solution (respiration and photosynthesis)

  useful as a transport medium - to move substances around you need a liquid. (blood)
• what differs between each amino acid?

  the R-group
• what is the simplist amino acid?


  glycine
• what is the R-group for glycine?


  hydrogen
• do all amino acids have the same basic structure?


  yes
• what is the basic amino acid structure?


  .

  
• how are the properties of proteins determined?


  by the aa sequence
• what is the test for protein?


  biuret test
• how do you do the biuret test?


  you put some albumin in a test tube

  add 1cm cubed of biuret with a pipette
• how can you tell if proteins are present using the biuret test


  the solution will turn a lilac colour
• what is a primary structure?


  The sequence of aa is known as the primary structure

  The aa chain is a polypeptide
• what is a secondary structure?

  H-bonding forms between the –COOH and the -NH2 of adjacent aa

  This results in the chains folding
• what is the tertiary structure?

  bonding between R-groups gives rise to a 3D shape