this peak is followed by a near-linear decline until B reaches zero and the last product -ethanol metabolized into acetaldehyde -is the sole remaining chemical species(of course, in the body the process continues , but here we are focusing on the first two steps) because we are mixing first -and zeroth-order kinetice,the shapes of the plots and the relative positions of the maxima will depend on the initial amount as well as the exact value of the rate constants(which again are highly subject dependent
The combination of first-order and zeroth-order reaction does make an interesting exercise,and its solution is in fact easier than the consecutive reactions usually considered in texts.Students and teachers are urged to use this,since it does pertain to a very well known phenomenon.