TOPIC 8.1 METABOLISM Flashcards
Definition of Metabolism
The sum total of all the reactions that occur in an organism to maintain life
Examples of metabolic chains
Glycolysis
Example of Metabolic cycles
Krebs cycle and Calvin Cycle
Definition of activation energy
The amount of energy required for a chemical reaction to occur
What do enzymes do to activation energy
Enzymes lower the activation energy of chemical reaction
Enzymes bind to the substrate which destabilize the bonds meaning less energy is needed and the reaction occurs at a faster rate
Exergonic reactions
The reactants contain more energy than the products and free energy released into the system
CATABOLIC
Endergonic reaction
Reactants contain less energy than the products free energy is lost to the system
ANABOLIC
What is an enzyme inhibitor
Molecule that disrupts the normal reaction pathway between an enzyme and substrate
What is competitive inhibition
When another molecule binds to the enzymes active site which blocks the active site and prevents substrate binding.
The effects can be reduced by increasing substrate concentration
What is non competitive inhibition
Molecule binds to a site which isnt the active site which causes a change to the shape of the enzymes active site.
This means the substrate can no longer bind to the active site. Substrate concentration cant negate this
Normal enzyme and substrate bonding
Substrate binds to the enzymes active site.
Active site has an induced fit to the substrate to optimally react which destabilizes the substrate leading to lowering the activation energy.
Which type of feedback controls metabolic pathways
End product inhibition which is negative feedback. End product inhibitor ensures levels of essential products are controlled
What happens in end product inhibition
If products levels build up the product inhibits the reaction pathway and decreases rate of further product formation
If product levels drop the reaction pathway remains untouched and rate of product increase
Calculation for rate of reaction
Rate of reaction = 1/time taken
Factors that affect enzyme activity
Temperature (increase due to increased collisions until denatured
pH (increase until pH denatures enzymes
Substrate Concentration (sharp increase but plateaus when all enzymes have been banded to)
