Steroid and thyroid hormones, Biology

Assignment Help:

Steroid and Thyroid Hormones

Cytoplasmic receptors for steroids are proteins with two subunits that bind to the steroid molecules. When both receptor sites are occupied by the steroid then the receptor-steroid complex migrates to the nucleus where one subunit ensures that the complex binds to the specific site on the chromatin. Then the receptor subunits separate and the other subunit interact directly with the adjacent region of DNA molecule resulting in the transcription of the DNA segment into mRNA.

Thyroid hormone acts in a similar manner except that the receptor is located in the nucleus. The major hormone secreted by thyroid is thyroxine (T4). It travels in blood attached to carrier proteins. Thyroid also secretes a small amount of triiodothyronine (T3). Carrier proteins have higher affinity for T4 and very little T4 is free in the plasma. Only the free T4 and T3 enter the cells. The rest of the bound T4 acts as a reservoir for slow release. The free T4 that enters the cell s also converted to T3 enzymatically. Therefore, T3 is the chemically more potent and active form of thyroid hormone.

552_Steroid and Thyroid Hormones.png

Figure:Steroid and Thyroid Hormones


Related Discussions:- Steroid and thyroid hormones

Absorption, Absorption The monosaccharides, amino acids and other prod...

Absorption The monosaccharides, amino acids and other products of digestion must be passed on to other tissues to be useful for the organism. The process by which the digested

What is the route of nutrients after digestion, Q. From the intestinal lume...

Q. From the intestinal lumen through to the tissues - what is the route of nutrients after digestion? Monosaccharides, mineral salts, amino acids and water are absorbed by the

Show artificial systems of classification of plants, Q. Show Artificial sys...

Q. Show Artificial systems of classification of plants? Carolus Linnaeus (1707-1778) popularly known as Carl Von Linne was born on May 1707 at Result, a small village in Smalan

What are the catalysts, Q. What are the catalysts? Catalysts are substa...

Q. What are the catalysts? Catalysts are substances that decrease the activation energy of a chemical reaction, facilitating it or making it energetically viable. The catalyst

Explain in brief about polymers, Explain in brief about Polymers In com...

Explain in brief about Polymers In comparison to metals and ceramics, polymers are weak and flexible. These are not popular as dental implant materials. Examples of polymeric m

Neurons, how does sodium and potassium ions maintain the resting petential ...

how does sodium and potassium ions maintain the resting petential of neurons

Explain nutrient cycling and their processes, Explain Nutrient Cycling and ...

Explain Nutrient Cycling and their processes? Two major processes are common to all ecosystems: nutrient cycling and the flow of energy. These two functions are carried out by

What are the major characteristics of the bryophytes, Q. What are the major...

Q. What are the major characteristics of the bryophytes? Bryophytes are nonvascular plants that is they do not have conductive tissues and they perform transport of nutrients a

Explain about the reproduction in fungi, Explain about the Reproduction in ...

Explain about the Reproduction in Fungi? Fungi, we have seen above, reproduce both sexually and asexually. Asexual mode of reproduction include budding, binary fission and more

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