However, use of the gal is deprecated by ISO 80000-3:2006. The gal is a derived unit, defined in terms of the centimeterâgramâsecond (CGS) base unit of length, the centimeter, and the second, which is the base unit of time in both the CGS and the modern SI system.
It has been shown experimentally that if the amount of the enzyme is kept constant and the substrate concentration is then gradually increased, the reaction velocity will increase until it reaches a maximum. After this point, increases in substrate concentration will not increase the velocity (delta A/delta T). This is represented graphically in Figure 8. It is theorized that when this maximum velocity had been reached, all of the available enzyme has been converted to ES, the enzyme substrate complex.
Obviously Vmax is the maximum rate that the reaction can proceed at. The reason Km increases with a competitive inhibitor is because the inhibitor is directly competing with the substrate for a fixed number of active sites on enzymes. Hence, Km increases.If there is a competitive inhibitor you will need more substrate to get the same 1/2 Vmax (this is why Km increases).m is the substrate concentration that is required for the reaction to occur at 1/2 Vmax. In other words, it is how much substrate is needed for the reaction to occur at 1/2 its max possible rate.