Can you explain secondary metabolites, Biology

Assignment Help:

Q. Can you explain Secondary Metabolites?

Secondary metabolites or secondary plant products are those macromolecules that lack nitrogen and arc of restricted occurrence and therefore of greater taxonomic importance the an primary metabolites. This group includes different kinds of compounds such as phenolics, alkaloids, terpenoids, etc. They are usually not involved in vital functions and are largely storage products or pigments.

Amongst the secondary metabolites, flavonoids, which are the commonest phenolic compounds of leaves, have been very useful for chemotaxonomic purposes. Both monocots and dicots have been extensively surveyed for these compounds which show structural variability and chemical stability besides widespread distribution. They can be rapidly and easily identified and provide important chemical characters for
taxonomic purposes. For example, 80 species of plants from the family Ulmaceae were investigated for their flavonoid chemistry by Ciannasi (1978). A majority of the species contain flavonols, but a few species have glyco-flavonol and these two types of flavonoid compounds are never present together in any species. Interestingly, enough, in most classical systems of classification, the family Ulmaceae is divided, into two subfamilies called Ulmoideae and Celtoideae which are aiso distinguishable

by the flavonoid chemistry. Therefore, morphological criteria combined with flavonoid dichotomy can be used to divide the family Ulmaceae (sensu lato) into two distinct families: family Ulmaceae (sensu stricto) characterised by the presence of flavonols, and family Celtaceae. characterised by the presence of glucoflavonols. Several other studies have used flavonoid chemistry for taxonomic purposes in families such as Arilidaceae, Cornaceae, Labiatae (Lamiaceae), Leguminosae (Fabaceae), Orchidaceae, Rutaceae, Lemnaceae and others.

A second group of secondary metabolites commonly examined by chemotaxonomists are the terpenes. Chemically speaking, these compounds can be classified on the basis of their molecular structure into monoterpenes, diterpenes, triterpenes, , sesquiterpenes, etc. and each group can be used for taxonomic purposes. For examp1e;;'the genus Salvia, 19 species could be distinctly identified and classified on the basis of their monoterpenes. The terpene composition was as 'useful as the morphological' characteristics in the analysis of introgression and hybridisation within the genus. Similarly, triterpenes and sesquiterpenes have been particularly important and useful in the classification of the families Cucurbitaceae and Coinpositae (Asteraceae) respectively.


Related Discussions:- Can you explain secondary metabolites

Explain sympatric and allopatric speciation, Sympatric OR allopatric specia...

Sympatric OR allopatric speciation Sympatry The development of new species within a population. Two Hebe sp living in the same location but with different chromosomal numb

Explain some ethological activities, Explain Some Ethological Activities ...

Explain Some Ethological Activities Comparative studies of behaviour or activities are also used in systematic for identification of organisms. The comparative study of the beh

How cells of neoplastic tumors obtain oxygen and nutrients, Q. How do cells...

Q. How do cells of neoplastic tumors obtain oxygen and nutrients and release wastes? In the neoplastic tumors a phenomenon called as angiogenesis occurs. The Angiogenesis is th

Explain strengthening the public health measures - anaemia, Explain Strengt...

Explain Strengthening the public health measures? Parasitic infestations and protozoal infections cause iron deficiency through loss of blood or destruction of red blood cells.

Inferior epigastric artery-other arterial conduits, Inferior Epigastric Art...

Inferior Epigastric Artery (I.) :  This is a branch of external iliac artery supplying the abdominal wall. It is raised as a free graft for CABG. The usual length availab

Describe the shape and size of proteins, Shape and size of protiens ...

Shape and size of protiens Fibrous proteins for example: keratin in hair, actin and myosin in muscles, and collagen. Globular proteins, for example enzymes and antibo

Obelia, why is obelia considered to of special interest in Zoology as an an...

why is obelia considered to of special interest in Zoology as an animal showing an intermediate grade of organisation?

Pathophysiology and medical mangement of acute renal failure, Pathophysiolo...

Pathophysiology of Acute Renal Failure It is usually reversible but the deviation of physiologic function can be extreme and mortality in pediatric age group remains high. Th

Meat snack products, S n a c k Products Meat snacks such as curls; ...

S n a c k Products Meat snacks such as curls; chips are made from sliced, whole meat and comminuted meat. Extruded snacks are made from meat and non meat ingredients. Extru

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd