A fresh leaf sample weighs 24.0 g. After drying it weighs 6.0 g…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A fresh leaf sample weighs . After drying it weighs . Burning the dry sample leaves of ash.
- How much water did the sample lose?
- What per cent of the fresh sample was water?
- What per cent of the dry matter was ash?
- How much organic matter burned away?
Need a reminder? The key ideaShow
Grinding a tissue in trichloroacetic acid and straining it gives the filtrate (the acid-soluble pool of small molecules) and the retentate (the acid-insoluble fraction of large molecules). Lipids are small but come down with the large ones inside membrane vesicles. Drying removes water; burning dry matter leaves ash, the inorganic elements. A cell is 70 to 90 per cent water. Primary metabolites have known roles; secondary metabolites include alkaloids, rubber, drugs, pigments and gums.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Water lost. .
Step 2. Water share. .
Step 3. Ash share. .
Step 4. Organic matter. .
Answer: ; ; ; .
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