Are enzymes involved in producing a colour change in yam

[cheyanne]

Question:
Madam Brown is a market endor.She sells ground provisions, e.g. yam, dasheen, etc. Madam Brown noticed that a freshly sut piece of yam turned brown after exposure to the air. However, when she rubbed it with lime or lemon juice it did not change colour. Desing and experiment to find out if an enzyme is involved in producing this colour change.

What I found out
There are 4 factors which affect enzymes:temperature, substrate concentration, enzyme concentration and pH.Enzymes perform better at the optimum pH 7. When the pH is raised above or below this value enzyme activity diminishes.

Lime or lemon juice is acidic

If the lemon juice was rubbed on befor the yam would not have turned brown at all or it owuld have taken less time to turn brown. so I'm guess if an acidic solution was rubbed on it would have turned brown faster

Any help or tips I recieve would be of great value.

[mith]

Why would it turn brown faster when clearly the lime juice made it turn brown slower?

[cheyanne]

sry my oopsy i meant to say that the alkaline solution would make it turn brown faster