Which statement is not true regarding substrate channeling?

a. it makes the kinetics of the complex so rapid as to prevent it from being the rate‑limiting step(s) of a pathway
b. it prevents intermediates from feeding into other pathways
c. it increases the local concentration of substrates
d. it prevents intermediates from diffusing away from the active sites

Answer:

It makes the kinetics of the complex so rapid as to prevent it from being the rate-limiting step(s) of a pathway  is not true regarding substrate channelling

Explanation:

Substrate channelling is the transfer of transitional metabolic products of one enzyme straightly to other enzyme or any active site without its release into solution.The metabolic pathway can be made more rapid and also efficient than it would actually be through channelling if enzymes could have been randomly designed. It occurs in many ways like in pyruvate dehydrogenase complex may be tryptophan synthase or can be dihydrofolate reductase thymidylate synthase.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.