2.1 Metabolic Pathways Flashcards
What are metabolic pathways?
Metabolic pathways are integrated and controlled pathways of enzyme-catalysed reactions within a cell
What are the 3 types of steps a metabolic pathway can have?
-Reversible steps
-Irreversible steps
-Alternative routes
What is an anabolic reaction?
The building up of large molecules from small molecules, this requires energy
What is a catabolic reaction?
The break down of large molecules into smaller molecules, this releases energy
What are metabolic pathways controlled by?
Metabolic pathways are controlled by the presence or absence of particular enzymes and the regulation of the rate of reaction of key enzymes
What is induced fit?
Induced fit is when the active site changes shape to better fit the substrate after the substrate binds
What molecule has a high affinity for the active site?
Substrates
What molecule has a low affinity for the active site?
Product(s)
What are the 3 types of inhibitors?
-Competitive inhibitors
-Non-competitive inhibitors
-Feedback inhibitors
Where do competitive inhibitors bind?
Active site
Can competitive inhibition be reversed?
Yes, through increasing substrate concentration
Where do non-competitive inhibitors bind?
At an allosteric site but change the shape of the active site preventing the substrate from binding
Can non-competitive inhibition be reversed?
No
When does feedback inhibition occur?
When the end product in the metabolic pathway reaches a critical concentration
How does feedback inhibition work?
The end-product inhibits an earlier enzyme, blocking the pathway, and so prevents further synthesis of the end-product
