biology!!

ok...so i've just had a mental block and was hoping biology people will be able to help me out here!! I'm just about to write up my biology plan for AS and the title is...'An experiment to find out how concentration of the substrate starch affects the rate of activity of the enzyme Amylase'
Now we are using potatos for this which contain starch...however the teacher went on about making up different substrate concentration solutions which i just dont get as i thought the substrate was in the potato? however she said that we should have the same size and number of potato discs each time and i just dont get it as how are you varying substrate concentration if you keep the amount of potato the same....sorry if i havnt described my problem very well but i really dont understand..any advice would be great!!

Reply 1

8EnglishRoses

Eh? Wrong forum and I don't really understand, I think you should ask your teacher to explain it again.

Reply 2

josee32

well no actually i meant to post it on here...as normally med applicants/students have very gd advice!! :biggrin:

i cant....im writing it up in the morning!! lol!!

Reply 3

Custer

I think your variable is temperature.

Reply 4

josee32

we are trying to find out the affects of substrate concentration on enzymatic acitivity....so substrate is the IV...surely?

Reply 5

Custer

sorry, i misread your post, your teacher modified the concentration of a solution which isnt potato, so must be for the enzyme not substrate. So I guess your variable has to be conc of amylase.

Reply 6

josee32

thats what i thought...however the piece of paper i have from her says
title: plan an experiment to find out how concentration of a particular substrate affects the rate of activity of a named enzyme.

Reply 7

martin101

well in that case using potatoes is a pile of crap because practically speaking the concentration of starch in a potato should be more or less the same throughout so there isnt a way of varying it by using different sizes of potato. I think your teacher has said something wrong or youre telling us something that aint the case because it doesnt make any sense as it stands