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A Handbook of Biology

Anabolic (biosynthetic) pathways

Catabolic pathways

Simpler molecules form complex

structures (Constructive process)

Complex molecules form simple

structures (destructive process)

It consumes energy.

It releases energy

E.g. Formation of acetic acid from

cholesterol, assembly of amino

acids to protein, photosynthesis etc.

E.g. Formation of lactic acid from

glucose (glycolysis), respiration

etc.



Metabolites are organic compounds taking part in metabolism.

THËÝ ÅRË ØF 2 TÝPËS:

Primary

metabolites:

They

have identifiable functions in

physiological

processes

and

necessary for life. E.g. amino

acids,

sugars,

nucleic

acids,

lipids, vitamins etc.

Secondary metabolites: They

are not directly involved in

normal growth, development

or reproduction. Many of these

are

useful

for

the

human

welfare

and

some

have

ecological importance.

1

2

SËÇØÑDÅRÝ

MËTÅBØLÏTËS

7

Polymeric

substances:

Rubber,

gums, cellulose etc.

6

5

4

3

2

1

Pigments: Carotenoids, Anthocyanins etc.

Alkaloids: Morphine, Codeine etc.

Terpenoids: Monoterpenes, Diterpenes etc.

Essential oils: Lemon grass oil etc.

Toxins: Abrin, Ricin etc.

Lectins: Concanavalin A

Drugs: Vinblastin, curcumin etc