Zusammenfassung der Ressource
8. Enzymes
Anmerkungen:
- A quarter of the genes in the human genome encodes enzymes
- Mediate the transformation of one form of energy to another
- Catalytic power
Anmerkungen:
- They catalyze by stabilizing transition states
- Active site
Anmerkungen:
- The particular site the catalysis takes place on the enzyme
- Proteins
Anmerkungen:
- Nearly all know enzymes are proteins
- capacity to specifically bind a very wide range of molecules
- Specificity
- Substrates
Anmerkungen:
- The very specific reactants enzymes choose to catalyze reactions with
- Proteolytic enzymes
Anmerkungen:
- These enzymes catalyse proteolysis
- Proteolysis
Anmerkungen:
- The hydrolysis of a peptide bond
- Hydrolysis of an ester bond
- Cofactors
Anmerkungen:
- Able to execute chemical reactions
- Holoenzyme
Anmerkungen:
- An enzyme with a cofactor
- Metals
- Coenzymes
Anmerkungen:
- Prosthetic groups
Anmerkungen:
- Cosubstrates
Anmerkungen:
- Loosely bound coenzymes.
They are like substrates and products, they bind to the enzymes and are released from it.
- Apoenzyme
Anmerkungen:
- An enzyme without a cofactor
- Free energy (G)
Anmerkungen:
- A thermodynamic property, that is a measure of useful energy to the energy that is capable of doing work
- ΔG
Anmerkungen:
- The free energy difference, ΔG, between reactants and products
Tells us whether the reaction will take place spontaneously
- 1. Exergonix
Anmerkungen:
- A reaction that takes place spontaneously --> ΔG is negative
- 2. Equilibrium
Anmerkungen:
- A system is at equilibrium and no net change can take place if ΔG is zero
- 3. Endergonic
Anmerkungen:
- A reaction cannot take place spontanously if ΔG is positive ( An input is required to drive such a reaction)
- 4. Independent of the path
Anmerkungen:
- ΔG of a reaction depends only on the free energy of the products minus the free energy of the reactants. The ΔG of a reaction is independent of the path of the transformation.
- 5. Provides no info about the rate
Anmerkungen:
- A negative ΔG indicates the a reaction CAN take place spontaneously, but doesn't specify whether it will proceed at a specifik rate
- Energy required
Anmerkungen:
- The energy required to initiate the conversion of reactants into products
Tells us the rate of the reaction
- ΔG°
Anmerkungen:
- ΔG°'
Anmerkungen:
- The standard free energy change at pH 7
- Keq'
Anmerkungen:
- The equilibrium constant under standard conditions