How do the two forms of amylase differ in their actions?

Question

alpha-amylase and beta-amylase how do they both differ from eachother in their actions?

Answer 1

alpha-amylase hydrolyzes saccharide bonds, which are those pointed at by the arrows in the figure, above. So imagine, a bunch of alpha-amylases randomly bouncing around (Brownian motion!) in among some extremely long starch molecules. Whenever a "mouth" - the enzymatic or active site - bounces against a saccharide bond, "snip", and the bond is broken (hydrolyzed as a water molecule is added "across" the saccharide bond). With that bond broken, the whole starch molecule is now in two pieces. The more "bites," the more and smaller pieces. To help you "identify" with alpha-amylase, you will be happy to know that most of you have lots of it in your saliva.

The beta-amylase PacMan is very picky and can only "chew" on the ends of a starch molecule, and only on one end and not both. It can only chew on the "reducing" end of starch, and that is the end far off the righthand side of the figure above. When beta-amylase does its job, it bites of maltose units - in other words, two glucose units at a time

Answer 2

That's from the wikipedia by the way. (wiki 'beta amylase')