March Mock Quick Revision Flashcards
What is the test for starch?
Few drops of iodine solution
What is the test for reducing sugars (glucose)?
- add equal volume of Benedict’s solution and mix
- heat in a 95˚C water bath for few minutes
What is the test for proteins?
Biuret Test
- add equal volume of 0.1mol/dm^3 potassium hydroxide solution and mix
- add few drops of 0.01mol/dm^3 copper sulfate solution and mix
What is the test for fats/ lipids?
- add equal volume of ethanol, and shake thoroughly
- add water
What is a positive test for starch (iodine solution)?
Yellow/ orange —> blue/ black
What is a positive test for reducing sugars (glucose) (Benedict’s test)?
Blue —> green —> orange —> red (depending on how much sugar present)
What is a positive test for protein (biuret test)?
Pale blue —> pale purple
What is a positive test for fats (lipids) (ethanol emulsion test)?
Clear —> cloudy
What is Fick’s Law?
Rate of diffusion ∝ (surface area x concentration difference) / thickness of membrane
What is transpiration?
The movement of water through and out of the plant (xylem)
What is translocation?
The movement of sugars and other chemicals/ sap (amino acids, sucrose, water) - (assimilates) made by the plant cells along the phloem (direction depends on time of year)
Which direction does translocation occur (dependent on time of year)
Down in summer
Up in spring
What is the main assimilate in translocation?
Sucrose - plant makes glucose but turns it into sucrose
What waterproofs the xylem?
Lignin
What is in between the phloem cells?
Sieve tube elements - porous cell walls so nutrients (cell sap) can flow between them