25-08-2014, 12:29 PM
VITAMINS, PIGMENTS, HARMONES
VITAMINS.pptx (Size: 1.2 MB / Downloads: 12)
INTRODUCTION:---
These are oily substance, not readily soluble in water and their biochemical functions are not well understood.
Example:- Their examples are vitamins A, D, E and K.
These vitamins are play more specialized roles in certain group of animals and in particular type of activities.
They function in the formation of a visual pigments (vitamins A), in the absorption of calcium and phosphorus from the vertebrate inestine (vitamins D), in the mitochondria system from inactivation (vitamins E) or in the formation of a blood clotting factor in vertebrates (vitamin K).
WATER SOLUBLE VITAMINS
Most of these are universally vitamins since they perform the same general function wherever they occur.
The common water- soluble vitamins of B complex such as B1, B2, B3, B4, B5, B6, B7, B8, B9, B10, B11 , and B12 and the vitamins C. Choline, inositol bioflavonoids are frequently included in this category.
HISTORY OF PIGMENTS
Naturally occurring pigments such as ochres and iron oxides have been used as colorants since prehistoric times. Archaeologists have uncovered evidence that early humans used paint for aesthetic purposes such as body decoration. Pigments and paint grinding equipment believed to be between 350,000 and 400,000 years old have been reported in a cave at Twin Rivers, near Lusaka, Zambia.
Before the Industrial Revolution, the range of color available for art and decorative uses was technically limited. Most of the pigments in use were earth and mineral pigments, or pigments of biological origin. Pigments from unusual sources such as botanical materials, animal waste, insects, and mollusks were harvested and traded over long distances. Some colors were costly or impossible to mix with the range of pigments that were available. Blue and purple came to be associated with royalty because of their expense.
CHLOROPHYLLS
Chlorophylls are greenish pigments which contain a porphyrin ring. This is a stable ring-shaped molecule around which electrons are free to migrate. Because the electrons move freely, the ring has the potential to gain or lose electrons easily, and thus the potential to provide energized electrons to other molecules. This is the fundamental process by which chlorophyll "captures" the energy of sunlight.
There are several kinds of chlorophyll, the most important being chlorophyll "a". This is the molecule which makes photosynthesis possible, by passing its energized electrons on to molecules which will manufacture sugars. All plants, algae, and cyanobacteria which photosynthesize contain chlorophyll "a". A second kind of chlorophyll is chlorophyll "b", which occurs only in "green algae" and in the plants. A third form of chlorophyll which is common is (not surprisingly) called chlorophyll "c", and is found only in the photosynthetic members of the Chromista as well as the dinoflagellates. The differences between the chlorophylls of these major groups was one of the first clues that they were not as closely related as previously thought.
GENERAL FUNCTIONS
The hormones conduct a wide variety of functions from growth, vegetative, sexual development, cellular oxidation to thermal production and the metabolism of carbohydrates proteins and fats.
The various function performed by hormones.
Regulatory or homeostatic function:- The hormones have regulatory effects of composition of the central nervous system (CNS).
Integrative function :- The integrative function of the hormones is reflected in the that they support the role of nervous system. The intergrative properties of the endocrine system are slow and steady whereas those of the nervous system are rapid.
Morphogenetic function:- The hormones govern the ontogenetic development of an individual from the embryonic to the adult state.