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

Lipids, Lipids All animal tissues contain lipids or fats as essential...

Lipids All animal tissues contain lipids or fats as essential components of cell membrane. It is also stored in certain tissues. Lipids are body's chief source of energy and

Ecosystem, what is the structure of ecosystem

what is the structure of ecosystem

Define food business and food technology, Define Food Business and Food Tec...

Define Food Business and Food Technology? The food business and food technology are practically inseparable. The food business may be characterized as: vulnerable to spoilage,

Advances in neurodiagnostic techniques, Advances in neurodiagnostic techniq...

Advances in neurodiagnostic techniques Major scientific and technology advances have made it easier to correlate behaviours suspected as having a neurological basis with actual

Explain systemic circulation in human biology, Explain Systemic Circulation...

Explain Systemic Circulation in human biology? In systemic circulation, oxygenated blood is pumped from the left atrium through the bicuspid valve, into the left ventricle, and

Explain leaf silhouettes, Leaf silhouettes Place a leaf on a sheet of w...

Leaf silhouettes Place a leaf on a sheet of white paper and hold it securely with thumb or finger. Press a piece of natural or artificial sponge next to an ink pad. With short,

Zoology, Classification of the Phylum Protozoa up to orders

Classification of the Phylum Protozoa up to orders

Detecting and resolving discrepancies, Detecting and resolving discrepancie...

Detecting and resolving discrepancies: Since the information selected to enter consciousness is usually about changes in the external and internal worlds, when there is a discrepan

Some important zoonoses-rabies , Some important zoonoses Zoonoses are ...

Some important zoonoses Zoonoses are a heterogeneous group of diseases with a variety of causative agents. On the basis of causative agents, they are grouped into bacterial, p

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