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

Magnetic resonance imaging (mri), M a g n etic resonance imagin...

M a g n etic resonance imaging (MRI): It is in use as a clinical diagnostic tool since 1980. The distribution of hydrogen nuclei (protons), present in cellular wa

Types of retaining structure, What are the types of evaluation of lateral e...

What are the types of evaluation of lateral earth forces acting on retaining structures? This section seeks to introduce you to the evaluation of lateral earth forces acting on

Dormant vegetative structures, Dormant Vegetative Structures You have ...

Dormant Vegetative Structures You have learnt that light a period of chilling or application of gibberellin often breaks seed dormancy and stimulates seed germination. Vegetat

Unconventional oilseed cakes/meal, Unconventional oilseed cakes/meal ...

Unconventional oilseed cakes/meal Deoiled sal (Shorea robusta) seed meal: It is a byproduct obtained after the extraction of oil from sal seeds. It is found to be high in NF

Male reproductive disorders-aplasia of epidydimis, Aplasia of epidydimis ...

Aplasia of epidydimis This condition is seen in only 1 or 2 % of young bulls and is marked by absence of one (more common) or both epididymis. Bulls having a single epidydimis

How is extracellular digestion related to cellular, How is extracellular di...

How is extracellular digestion related to cellular and tissue specialization? Several of specialized cells and tissues appeared with extracellular digestion to give enzymes and

Spermiogenesis - spermatogenesis, Spermiogenesis - Spermatogenesis At ...

Spermiogenesis - Spermatogenesis At the end of the meiosis the spermatids appear as simple spherical cells with a centrally located nucleus. Their differentiation into sperm r

Most important allosteric effector of glycolysis in liver, Name the most im...

Name the most important allosteric effector of glycolysis in the liver. Fructose-2,6-bisphosphate  is the most important allosteric effector of glycolysis  in the liver

Express krebs cycle photosystem ii, Calvin cycle electron transport chain g...

Calvin cycle electron transport chain glycolysis Kreb's cycle photosystem II.

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