Is there life in there? video experiment - observations
These observations accompany our video – use them for your own analysis
Visual inspection
Sample A
Small, similar
grains, dark colour
Response to hydration
No change observed
Reducing sugar test
Bright blue, no
sugar present
No change
Bright blue, no
sugar present
No change
Clear, no lipids
present
Yellow, no starch
present
Clear, no lipids
present
Dark brown/black,
starch present
Biuret test for protein
Ethanol test for lipids
Iodine test for starch
Sample B
Mostly small
grains, some larger
grains of lighter
colour
Gas produced, fast
at first then slowed.
Chemical reaction?
Sample C
Mixed grains,
some larger and
white
Repelled water,
some particles
expanded and
floated
Cloudy, murky
blue
Purple,
considerable
colour change,
protein present
Cloudy, lipids
present
Black, starch
present
This resource first appeared in ‘Big Picture: Space Biology’ in June 2015. Published by the Wellcome
Trust, a charity registered in England and Wales, no. 210183.
bigpictureeducation.com