Define role in growth and cellular differentiation, Biology

Assignment Help:

Define Role in growth and cellular Differentiation?

The growth and differentiation of epithelial cells throughout the body are especially affected by vitamin A deficiency.  In addition, goblet cell numbers we reduced in epithelial tissues and as a consequence, mucous secretions diminish. Cells lining protective tissue surfaces fail to regenerate and differentiate; hence they flatten and accumulate keratin.  Classical symptoms of xerosis (drying or non-wet ability) and desquamation of  dead surface cells as seen in ocular tissue (i.e. xerophthalmia) are the external  evidence of the changes also occurring to various degrees in internal epithelial  tissues. Current understanding of the mechanism of vitamin A action within cells outside the visual cycle is that cellular functions are mediated through specific nuclear receptors. Binding with specific isomers of retinoic acid (i.e.all Tran- and 9-cis-retinoic acid) activates these receptors. Activated receptors bind to DNA response elements located upstream of specific genes to regulate the level of expression of those genes. These retinoid-activated genes regulate the synthesis of a large number of proteins vital to maintaining normal physiologic functions. There may, however be other mechanisms of action that are as yet undiscovered.

 


Related Discussions:- Define role in growth and cellular differentiation

Define multiple tube fermentation test, Define Most Probable Number Test (M...

Define Most Probable Number Test (Multiple Tube Fermentation Test)? Presence of coliforms in the water sample can be detected by performing multiple tube fermentation test whic

Define the iodine test - carbohydrates, Define the Iodine Test - Carbohydra...

Define the Iodine Test - Carbohydrates? This test is given by polysaccharides and is not given by monosaccharides or disaccharides. Principle Iodine forms a coloured ad

What is a biologic failure, What is A biologic Failure A biologic Fail...

What is A biologic Failure A biologic Failure can be defined as the inadequacy of the host to establish or to maintain osseointegration. The inability to establish osseoint

The two regulation systems of glycogen metabolism, Mention the two regulati...

Mention the two regulation systems of glycogen metabolism. There is a hormonal regulation system functioning  in the muscle and liver which regulates  the glycogen metabolism.

Excretion in flatworm, EXCRETIO N IN FLATWORM - Main organs are flame ...

EXCRETIO N IN FLATWORM - Main organs are flame cells, having bundle of cillia. It receives solute and water from surrounding tissue fluid by ultra filtration & discharge th

Hormones in metamorphosis of amphibia, Hormones in Metamorphosis of Amphibi...

Hormones in Metamorphosis of Amphibia In amphibians, the changes that take place during metamorphosis are brought about by hormonal secretions of the thyroid gland. The first

Theory of embryology -recapitulation theory / biogenetic law, RECAPITUL A ...

RECAPITUL A TIO N THEORY / BIOGENETIC LAW It was proposed by Muller & Haeckel on the basis of Baer's law. According to it, in the development of animal phylum characters

Johne''s disease, J o h n e ' s disease It is also known as parat...

J o h n e ' s disease It is also known as paratuberculosis characterized by chronic enteritis and progressive weakness in dairy animals. E t iology: Mycobac

Define the recommended dietary allowances of vitamin k, Define the Recommen...

Define the Recommended Dietary Allowances of Vitamin K? Recommended dietary intakes have not been suggested for different age groups or gentler. The safe levels of intake have

Explain microorganisms associated with the raw foods, Explain Microorganism...

Explain Microorganisms Associated With The Raw Foods? Foods of animal and plant origin are in direct contact with air, soil and water and get contaminated with the microorganis

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