Methabolic Pathways

Definition: a chain or cycle of reactions that are catalysed by enzymes

• Definition: a chain or cycle of reactions that are catalysed by enzymes

• reactions happen mostly at small steps

• Cycle pathways - the end product is used to start the pathway, such as in Krebs Cycle

add krebs cycle and glycolysis 

 

Enzymes and activation energy

• Activation Energy: min. of energy required for a reaction to take place

  • is used to break or weaken the bonds in the substrates

• binding of enzymes ⇾ lower the the activation energy 

• Activation Energy ⇾  + rate of reaction 

 

Types of enzyme inhibitors

• Definition: enzyme inhibitors bind to enzymes and reduce their activity 

• Competitive:

  • competes for the same site - is similar to the substrate

  • interferes with the active site ⇾ enzyme can not bind

  • does not modify the active site 

  • + substrate = - effect of the inhibitor

​

​

​

​

​

​

​

​

​

​

​

​

​

​

• Non-Competitive:

  • binds to a different location than the active site

  • changes the shape of the enzyme ⇾ enzyme can't bind

  • + substrate ⇾ does not change the impact of the inhibitor 

 

add graph

​

​

​

​

​

​

​

​

​

​

​

 

End-product inhibition 

• form of non-competitive inhibition: the end product binds to the allosteric site - inhibits products to be produced

• allosteric interactions ⇾ happens away from the active site ⇾ on the allosteric site

• excess of end product = stops the pathway 

• Example: amino acid threonine is transformed in isoleucine

 

 

 

 

 

 

 

 

 

 

 

 

​
 

• high concentration of isoleucine ⇾ makes isoleucine bind to the allosteric site of the first enzyme, threonine deaminase 

​

 

Bioinformatics and new antimalarial drugs

• research of metabolic pathways is facilitated through chemogenomics

• chemogenomics: a range of target sites and chemicals that work on those target sites are identified for each organism

• those informations create a database used to help find cure for diseases

• Example: new anti-malarial drugs

  • increasing drug resistance of the pathogen 

  • need to develop new drugs ⇾ identification of those

 

Calculating rate of reactions

• measure rate of disappearance of substrate

• measure rate of appearance of product

 

add graph

​