Unit 2.1 Metabolic Pathways Flashcards
What are metabolic pathways?
Metabolic pathways are integrated and controlled pathways of enzyme catalysed reactions within a cell
What types of things can happen with steps of metabolic pathways?
-They can have reversible steps
-They can have irreversible steps
-They can have alternative routes
What happens in an anabolic reaction?
Anabolic reactions build up larger molecules from smaller molecules and require energy to do so
What happens in a catabolic reaction?
Catabolic reactions break down a larger molecules into smaller molecules and release energy when doing this.
What types of protein are embedded in membranes?
-Protein pumps
-protein pores
-Enzymes
How are metabolic pathways controlled?
Metabolic pathways are controlled by the presence or absence of particular enzymes
And by the regulation of the rate of reaction of key enzymes
What is meant by ‘the induced fit model’?
Induced fit occurs when the active site of an enzyme changes shape to better fit the substrate after it binds
What can we say about the relationship between the active site and substrate?
The substrate has a high affinity for the active site
What can we say about the relationship between the active site and products of the enzyme controlled reaction?
The products have a low affinity for the active site this allows them to leave the active site
What instances may trigger a reversible reaction to take place?
-removal of a product
-presence of a substrate
What is meant by a competitive inhibitor?
A competitive inhibitor is an inhibitor that binds to the active site of an enzyme preventing the substrate from binding to it.
What can be done to reverse competitive inhibition?
Increasing the substrate concentration
What is meant by a non-competitive inhibitor
A non-competitive inhibitor is an inhibitor that binds away from the active site instead binding to the allosteric site and changing the shape of the active site of the enzyme preventing substrate from binding to the active site
What can we do to reverse non-competetive inhibition?
Nothing, increasing substrate concentration has no effect on non-competitive inhibition
How does feedback inhibition work?
When the end product of a metabolic pathway reaches a critical concentration the end product will then bind to an earlier enzyme in the pathway (by competitive inhibition or non-competitive it can do both) and prevent the further synthesis of the end product
