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Title: What is the mechanism of a competitive inhibition? Post by: aidan on Feb 21, 2014 Why does Km increases in competitive inhibition?
Title: Re: What is the mechanism of a competitive inhibition? Post by: padre on Feb 21, 2014 Because when there is a competitive inhibitor present (i.e. a substance which competes with the 'correct' substrate for a place within the enzyme active site), that means that the reaction proceeds more slowly (at a lower rate) for any given substrate concentration.
More substrate is required to successfully 'saturate' the enzyme present, and minimise the effect of the inhibitor, i.e. the Michaelis-Menten curve gets less steep, and reaches an asymptote (Vmax) at a point further towards towards the right hand side of the graph (at a higher substrate concentration). Since Km is the substrate concentration at half-Vmax, Km also gets shifted to the right, i.e. it increases. |