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

Metabolism of phenylalanine, The metabolism of phenylalanine will now be ta...

The metabolism of phenylalanine will now be taken in some detail, as two inborn errors of metabolism are known which affect this pathway. The Phenylalanine is 1st hydroxylated by p

Heat removal of gutta percha-endodontics principles, Heat removal of Gutta ...

Heat removal of Gutta percha: -    Heated plugger. -    Touch-N-Heat or system B used to thermo soften and remove gutta-percha from root canal systems. -    The cross-sectional

Explain mode of feeding, Normal 0 false false false EN-...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4 Mode of feeding

Digestive system - pharynx, PHARYN X - Commom system between digestive...

PHARYN X - Commom system between digestive system and respiratory system. In it gullet and glottis present.Gullet leads to oesophagus. Glottis lead to trachea. Wall of p

Explain the feeding process for preschoolers, Explain the Feeding process f...

Explain the Feeding process for Preschoolers? The word preschool children, you may be aware, is used for children less than six years of age. After the first year, there is a s

From molecules to the first cell, From Molecules to the First Cell The ...

From Molecules to the First Cell The prebiotic conditions on the earth in all probability were volcanic eruptions, lightning and heavy rains. There was no trace of free oxygen

Explain the endocrine gland and the exocrine gland, What is the difference ...

What is the difference between the endocrine gland and the exocrine gland? Endocrine gland is a gland whose secretions (known as hormones) are collected by the blood and reach

What are steroid hormones , Cholesterol is the precursor of the five major...

Cholesterol is the precursor of the five major classes of steroid hormones.The synthesis of steroid hormones is initiated by the removal of a six-carbon unit  from  carbon  20  of

Phases of seed formation, Phases of Seed Formation The process of seed...

Phases of Seed Formation The process of seed formation can be divided into two phases: The division phase, in which fertilised egg divides mitotically and complet

What is cytogenetics, What is Cytogenetics? Before the advent of modern...

What is Cytogenetics? Before the advent of modern technology, the American biologists Thomas Hunt Morgan, G.W. Beadle, H. Sturtevant, Barbara McClintock, and others contributed

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