4 mistakes learners make with enzymes and digestion, each one named and explained.
An enzyme is a catalyst with a shape, and everything that stops it working stops it by changing that shape.
You write that the enzyme died at 60 degrees C.
Enzymes come from living things and they stop working, so dying is the obvious word.
Question. What happens to an enzyme heated well above its optimum?
A common answer. it dies
The answer. it denatures: its shape changes so the substrate no longer fits
Why. An enzyme is a protein, not an organism. It was never alive, so it cannot die.
Say denatured, and then say what changed shape and why that stops it working.
You say the reaction stopped because the enzyme ran out.
Everything else in a reaction gets used up, so the enzyme looks like another ingredient.
Question. A reaction catalysed by an enzyme stops. The substrate has all gone. What has happened to the enzyme?
A common answer. it has been used up too
The answer. it is unchanged and ready to work again
Why. A catalyst speeds a reaction up without being used up, which is why a little goes a long way.
If it is used up it is a reactant, not a catalyst.
You say protein breaks down into glucose, or starch into amino acids.
The words are learned as two separate lists, and nothing in them says which pairs with which.
Question. What does protein break down into?
A common answer. glucose
The answer. amino acids
Why. Starch gives glucose, protein gives amino acids, and lipids give fatty acids and glycerol.
Learn each polymer with its monomer attached, as a pair, never as two lists.
You say an enzyme in the gut breaks down food, without saying which kind.
Digestion is one process from the outside, so one worker for the whole job seems reasonable.
Question. Can amylase break down protein?
A common answer. yes, it is a digestive enzyme
The answer. no. Its active site fits starch and nothing else
Why. The shape of the active site is what matches one substrate, so each enzyme has one job.
Name the enzyme and the substrate together, or the answer is not finished.
WAJD spots these patterns in your child's answers and names the one behind their wrong answers, instead of just marking them wrong.