starch (testing for starch)

Question 1

what colour does the leaf change to when it’s negative for starch?

Answer 1

brown + yellow

Question 2

what foods are made up of starch?

Answer 2

rice, potatoes, pasta, grains

Question 3

what colour does the leaf chnage when its positive for starch?

Answer 3

black + purple + blue

Question 4

examples of veggies that store starch in their roots

Answer 4

potatoes and carrots

Question 5

what r the stepsto testing a leaf for starch?

Answer 5

put the leaf in a beaker of boiling water for 1 minute (to stop chemical reactions)

transfer the leaf into boiling ethanol (to remove green pigment)

add or dip the leaf back into hot water (to soften the leaf)

gently spread the leaf and add iodine solution

Question 6

why is it important to remove green colour from the leaf before adding iodine?

Answer 6

so the colour of the iodine solution or result can be seen clearly

Question 7

where can starch be stored in a plant?

Answer 7

in the roots, stem or leaves

Question 8

why is a leaf boiled in water before being tested for starch?

Answer 8

remove the waxy cuticle layer

Question 9

why is starch a good storage molecule?

Answer 9

it is insoluble and therefore dosen’t affect the water potential of the cell

Question 10

why is the leaf put in ethanol?

Answer 10

remove chlorophyll to stop the rate of photosynthesis

Question 11

what is dangerous about ethanol?

Answer 11

flammable