GENERAL PHYSIOLOGY O *? ? ? 



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//. Chemical constituents of Protoplasm. 



A. Chemical elements necessary to life and growth- 

 Complete water culture for seedlings contains the following: 



KNO 3 1 gm. 



MgSO 4 0.5gm. 



CaSO 4 0.5gm. 



KH 2 PO 4 O.ogm. 



NaCl 0.5gm. 



NaCl 3 3-4 drops of 10% soln. 



Dist. H 2 O 1000 c.c. Solution to be heated to 100 C. for 



5 minutes. 



Certain members of the class will make up the whole solution 

 for control, others will omit one element. Compare the rate of 

 growth and general appearance of seedlings with roots placed in 

 the different solutions during a period of several weeks. What is 

 the apparent function of each element in the medium? What is 

 the source of carbon? 



B. The more important elements in protoplasm 



1. Carbonsubstance chars upon heating in dry test tube 

 (flour, sugar, bean, etc.). 



2. Hydrogen heat dried material as for carbon and note con- 

 densation of H 2 O in upper part of tube. (Flour, bean, etc.). 



3. Oxygen dry material; test tube closed with cork having 

 two holes; glass tube through one hole to end of tube and connected 

 with gas jet; the other connects with Bunsen burner. Pass gas 

 through the tube until the air is displaced. Light the burner and 

 heat the tube. The hydrogen is burned to H 2 O by O 2 in the 

 material. (Flour). 



4. Nitrogen heat with soda-lime NH 3 is given off. Test by 

 its action on litmus and cone. HC1. (Flour, bean, etc.). 



5. Sulphur -boil with strong HNO 3 . Dilute and filter if neces- 

 sary BaCl 2 gives white precipitate of BaSO 4 . (Flour, white of 

 egg). 



6. Phosphorus to half of above solution add ammonium 

 molybdate and heat. Yellow ppt. indicates P. (Flour, etc.). 



C. The chief way in which these elements are combined in 

 protoplasm. 



