



Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
These are the lab notes of Botany. Key important points are: Biochemical Changes, Investigation, Fruit, More Particularly, Results Implicating, Hemicellulosic, Cellulosic Cell Wall, Fruit Softening, Polygalacturonase, Tomato Cultivars
Typology: Study notes
1 / 6
This page cannot be seen from the preview
Don't miss anything!
According to an old country song by John Denver, the only two things money can't buy are true love and homegrown tomatoes (I am being honest here, feel free to check out the following link on “youtube” if you don’t believe me:
ripening and, more particularly, the changes that bring about fruit softening. In this fruit, despite some results implicating the hemicellulosic and cellulosic cell wall fractions in fruit softening, the most recent work in the area has focused on the pectic fractions. In particular, there has been much interest in the polyuronide- solubilizing enzyme, polygalacturonase. Its activity rises dramatically during ripening, and a close correlation between polygalacturonase and pericarp softening has been demonstrated in a range of tomato cultivars. Naturally, tomatoes unevenly ripen, showing darker green patches when unripe and variable redness when ripe -- traits that still show up in garden-variety and heirloom breeds. However, in the late 1920s, commercial breeders stumbled across a natural mutation that caused tomatoes to ripen uniformly -- from an even shade of light green to an even shade of red. This "uniform ripening" mutation has become indispensable to the $2 billion a year U.S. commercial tomato market, showing up in almost all tomatoes produced for grocery stores. The uniform redness makes it ideal for groceries, where customers expect evenly colored, red fruit.
breeders select for, eliminates this protein in the fruit, therefore reducing sugar
The act of ripening requires the expression and action of an enzyme protein to break down structural cell wall polysaccharides to smaller units and monosaccharides. So there should be a change in both sugar content and protein
Biochemical assays to be used in this Laboratory
Benedict's reagent assay procedure for reducing
sugars:
This reagent contains 100 g sodium carbonate and 173 g sodium citrate dihydrate in a final volume of 850 mL water. Slowly, with stirring, add a solution of 17.3 g copper sulfate pentahydrate in 100 mL of water. Bring the final volume to one liter.
The blue copper (II) ions from copper (II) sulfate are reduced to red copper (I)
changes observed. The red copper (I) oxide formed is insoluble in water and is precipitated out of solution. This accounts for the precipitate formed. As the concentration of reducing sugar increases, the nearer the final color is to brick-red and the greater the precipitate formed.
seen during this test are the same as with Benedict's solution. In this assay, samples are heated in a 55 oC water bath for 10-20 minutes. Ketopentoses demonstrate a positive reaction within 10 minutes, while ketohexoses take about 20 minutes to react.
Bradford assay Procedure:
The Bradford assay is a very popular protein assay method because it is simple, rapid, inexpensive and sensitive. The Bradford assay works by the action of Coomassie brilliant blue G-250 dye, which specifically binds to proteins at arginine, tryptophan, tyrosine, histidine and phenylalanine residues. Advantages
Disadvantages
Procedure:
Tube μl BSA μl H 2 O μg protein added 1 0.0 30.0 0. 2 0.0 30.0 0. 3 5.0 25.0 5. 4 5.0 25.0 5. 5 10.0 20.0 10. 6 10.0 20.0 10. 7 15.0 15.0 15. 8 15.0 15.0 15. 9 20.0 10.0 20. 10 20.0 10.0 20. 11 25.0 5.0 25. 12 25.0 5.0 25. 13 30.0 0.0 30.