This is the anbalogy discussed in class, for cooperativity in enzymes.

S  =  number of people looking for restaurants
E  =  number of empty-looking restaurants
C1 =  number of crowded restaurants
P  =  people who finished eating

People go in, sometimes out without eating (they did not like the menu?), but
once that they sit, they finish dinner - this explains the assumption that
C1 -> P+E and C2 -> P+C1 are irreversible as well as the reversibility of the
other reactions.

The assumption is that the total number of restaurants (and places in them, 
if you want to be more precise, but let us say there are 2 single tables in
each restaurant) is small compared to S and all the rates.

What about k3 >> k1, as needed for K1 >> K2?  
Well, this is just the fact that one tends to think that a restaurant is
better if it looks crowded, and hence customers are more likely to come in.

Sigmoidal vs MM shape:

When there is a large number of hungry people, more are finishing per unit of
time than compared to the non-cooperative case, because they are more likely
to have walked into restaurants to begin with (since most restaurants are very
crowded).

When there are very few people, on the other hand, restaurants look empty;
thus people take longer to make up their minds, so the rate at which people
finish eating is lower than in the noncooperative case.


Allosteric effects in addition to cooperativity (as in those experimental
results shown in the slides): perhaps a curtain is sometimes drawn, obscuring
the view of the restaurant and hence decreasing the cooperativity effect?