metabolism overview

• metabolism is catalysed by 6 classes of reaction
• define metabolism


  collection of coupled and interlinked series of chemical reactions which starts with a particular molecule and converts it to some other molecule/molecules
• function of metabolism

  • extract biologically useful energy from cells to environment
  • synthesize building blocks of the cells
• metabolism in 4 points

  • 2 types of reaction
  • 6 types of enzyme catalysed reactions
  • role of co-factors and "activated carriers"
  • identify major steps of energy extraction from carbon fuels
• what are the 2 types of reactions in metabolism?

  catabolic and anabolic
• what are catabolic reactions?


  extracting useful forms of energy
• what are anabolic reactions?


  generation of complex structures from simple ones
• what do anabolic reactions require?


  energy inputted from catabolism
• what are the enzyme catalysed reactions in metabolism?

  • oxidation-reduction reactions
  • ligation requiring ATP cleavage
  • isomerization
  • (functional) group transfer
  • hydrolytic
  • addition/removal of function group
• define functional group 


  specific group of atoms with is responsible for the chemical reactions of that group
• activated carriers are conserved through evolution
• examples of activated carriers


  ATP, FADH2, acetyl CoA
• OILRIG stands for


  oxidation is loss (of electrons), reduction is gain (of electrons)
• Is gain of hydrogen ions oxidation or reduction?


  oxidation
• ligation requiring ATP cleavage 


  • energy required for the reaction to occur, in the form of ATP, therefore is an energy dependent reaction
• isomerisation uses enzymes to move


  functional groups and change the shape of molecules
• functional group transfer is when 


  group moves from one molecule to another
• hydrolytic reaction is the


  addition of water to a molecule
• addition/ removal of a functional group is also known as 


  carbon bond cleavage
• carbon bond cleavage is not ATP dependent
• anabolic carbon bond cleavage is when a single C-C bond is made from C-H
• catabolic carbon bond cleavage is when a C=C bond is made from C-C
• activated carriers

  • thermodynamically unstable
  • kinetically stable
• why are activated carriers thermodynamically unstable?

  lots of free enrgy would be released if the reaction was allowed to proceed
• when are activated carriers kinetically stable?

  in the absence of specific catalysts
• Is ATP to ADP catabolism or anabolism?


  catabolism
• more reduced carbon source, the more energy is stored in the molecule. This is because


  more electrons can be re-arranged towards oxygen
• 3 broad stages to catabolism 


  1. conversion of diverse and complex molecules to simpler
  2. converging to formation of acetyl CoA
  3. citric acid cycle, oxidative phosphorylation