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

Explain about the basidiomycota - fungi, Explain about the Basidiomycota - ...

Explain about the Basidiomycota - Fungi? Basidiomycota - Fungi in this division are called basidiomycetes or club fungi. Sexual structure is known as basidium, which is club-sh

Is dwarf pampas grass invasive, Is dwarf pampas grass invasive? No. the...

Is dwarf pampas grass invasive? No. the root system is shallow and extends only as far as the plant is large. Though if the irrigation system is installed poorly and the pipes

Fate maps, Fate Maps The details of the procedure of gastrulation are...

Fate Maps The details of the procedure of gastrulation are not simple to understand without the knowledge of positions of the cells of the future germinal layers in the blast

Mass dispersal - population dispersal, Mass Dispersal - Population Dispersa...

Mass Dispersal - Population Dispersal A population is inherently dynamic in nature since individuals are always leaving or entering the populations. But such changes normally

Vertebrate eye - adult eye, Vertebrate Eye - Adult Eye There are no m...

Vertebrate Eye - Adult Eye There are no main differences in the structure or composition of the eyes among different vertebrates. This should be clear to you from the diagram

Disorders associated with copulation and ejaculation, Disorders associated ...

Disorders associated with copulation and ejaculation Lack of libido refers to too long “reaction time” to complete absence of sexual desire for females in standing heat. The i

Phylum annelida, what so special for phylum annelida

what so special for phylum annelida

Eye testing and its significance, Eye complications are very common in pati...

Eye complications are very common in patients with diabetes. In fact, diabetes related eye diseases may not produce symptoms for a very long time and hence, it remains undetected t

Somatic and germline gene therapy, All the cells present in the body contai...

All the cells present in the body contain genes and an approach targeted to modulate the expression of genes is known as gene therapy. This novel approach has emerged by the end of

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