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

How different are fecundation in osteichthyes, How different are fecundatio...

How different are fecundation in osteichthyes and in chondrichthyes? In chondrichthyes fecundation is internal by means of copulation. In osteichthyes fecundation generally is

Explain the term antioxidants, Normal 0 false false false ...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Poising capacity of food, As redox conditions change, there will be some re...

As redox conditions change, there will be some resistance to change in a food's redox potential. This is known as poising capacity of food. This capacity is dependent on the concen

How does vitamin c act in the body, Q. How does vitamin C act in the body? ...

Q. How does vitamin C act in the body? What is the harm caused by insufficiency of vitamin C? Why was this deficiency also known as "sailors' disease"? Vitamin C, or ascorbic a

Scientific name, what is a scientific name of mango?

what is a scientific name of mango?

DNA damaged by alkylating agents, Q. DNA damaged by alkylating agents? ...

Q. DNA damaged by alkylating agents? 1. Some simple alkylating agents 2. Illustrations of products of alkylating agents 3.Many of these products can be repaired by excision rep

Polypeptide chains of hemoglobin, Q. In sickle cell anemia, a hereditary di...

Q. In sickle cell anemia, a hereditary disease, there is replacement of one amino acid by another in one of the four polypeptide chains of hemoglobin. In this case are all of the s

Define estimation of iron in any solution - minerals, Define Estimation of ...

Define Estimation of Iron in any Solution? Iron can be determined calorimetrically. The principle is described next. Principle The iron is determined in the solution or d

Nutrition, difference between holophytic nutrition and holozoic nutrition.

difference between holophytic nutrition and holozoic nutrition.

Demography, Demography : This is the study of populations. In the other wor...

Demography : This is the study of populations. In the other words demography is the statistical study of human population. This may be a very general science which can be applied t

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