Bioenergetic's and important molecules
Bioenergetics: Is the flow of energy through living organisms
This energy is used to overcome the second law of thermodynamics
Living systems become more ordered, Living systems use energy to overcome local entropy
Disorder within the surrounding increases
Entropy within the universe increases
For organisms to grow, cells need energy, precursor metabolites and reducing power. Metabolism is: All teh chemical reactions going on in an organism
Use of food to produce energy
Use of food to create building blocks
Use of energy to run cellular processes
Use of building blocks and energy to create larger, more complex molecules
aseries of enxymatic reactions
Catabolism: Reaction breakdown the foodstuffs that are taken is, These reaction realease energy, simple compounds and reducing power.
Anabolism: Biosynthetic reactions used by a cell to make new material and larger molecules, These reactions use energy, simple compounds and the reducing power released in catabolism
Catabolism:
Degradative
Oxidative
Energy yielding
Uses a variety of starting materials
Has well defined products
Uses NAD+ or NADP+
Anabolism:
Synthetic
Reductive
Energy requiring
Has well defined starting materials
Has a variety of products
Uses NADPH
When looking at Energy changes we need to measure:
Internal Energy: (E) Total energy of the system
Enthalpy: (H) Heat content
Entropy: (S) Degree of disorder
Gibbs Free Energy: (G) energy available to do work
Temperature: (T) Temperature of the system in Kelvin
Free energy is related to the total chemical energy of the system and hence to the chemical stability of the system
If Free Energy is high we have a potentially unstable system and the system will tend to go to a lower free energy state - Likely to be spontaneous
If change in free energy is zero, the system is at equilibrium, To shift a system from equilibrium energy will need to be put in.
Exergonic: Release energy
Endergonic: Require energy
Living organisms maintain a steady state. This is not an equilibrium.
Enzymes change the rate of reaction but not the overall energy potential - They lower activation energy by providing a favourable pathway.
ATP: Acts as an energy carrier - When hydrolysed, energy is released
NAD+ and NADP+ these can be oxidised - accept two electrons and a proton
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NADH and NADPH these can be reduced
FAD has similar functions to NAD+, it is an electron carrier