Firstorder Rate Processes

Macroscopic changes in the concentration (or other extensive quantity) of a substance tend to be exponential kinet-ically; in other words, first order in rate expression. This is exemplified by the phenomena of bacterial growth, radioactive decay, enzyme decay, pharmacokinetics (ie, kinetics of drug, absorption, etc), and many other chemical reactions and food processes. This is simply because the behavior of any one bacterium (atom, pair of reactive molecules) is governed by the law of chance. For any one bacterium and such there is a well-defined probability that it

The rate of decrease of people in the room (decay of radioactivity, enzyme activity, or food quality, and microbial death rate in sterilization process), that is, —dN/dt, is dependent on the number of people at that time. The rate constant k, though, is independent of both time and the number of people (or other quantity such as enzyme concentration, radioactivity, etc). The half-life (t1/2) of an exponential decay function is the time required for the population to become half of its original number; namely, ln^ = ln2 N

Instead of decay, for growth such as cell culture after the lag phase, the rate is increasing (positive instead of negative in equation 6), and so the population doubling time is

Sleeping Sanctuary

Sleeping Sanctuary

Salvation For The Sleep Deprived The Ultimate Guide To Sleeping, Napping, Resting And  Restoring Your Energy. Of the many things that we do just instinctively and do not give much  of a thought to, sleep is probably the most prominent one. Most of us sleep only because we have to. We sleep because we cannot stay awake all 24 hours in the day.

Get My Free Ebook


Post a comment