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

What is the function of the immune system, What is the function of the immu...

What is the function of the immune system? The immune system performs exact defense against agents, the antigens, that are foreign or harmful to the body. Exogenous antigens

What are the specialized structures help adhesion cell, What are the specia...

What are the specialized structures that help the adhesion between cells? The structures responsible for the union of the epithelial cells are known as cell junctions. The main

What does secondary productivity in an ecosystem indicate, a) What does sec...

a) What does secondary productivity in an ecosystem indicate? b) List any two factors by which productivity is limited in aquatic ecosystems

Microorganisms on on basis of nutrient degradation capacity, Q. Microorgani...

Q. Microorganisms on On basis of nutrient degradation capacity? On basis of nutrient degradation capacity: - Proteolytic: Microorganisms, which are capable of protein degra

Binomial nomenclature, Binomial Nomenclature The modern system of clas...

Binomial Nomenclature The modern system of classification (Binomial nomenclature) accepted by biologists today was proposed in 1758 by the Swedish botanist Linnaeus (1707-1778

Microtubules, MICROTUBULES Discovered by De Robertis and Franchi ...

MICROTUBULES Discovered by De Robertis and Franchi . Term given by Slautterback . These are hollow structures, consists of tubulin protein. Each protein diamer

Explain database search, Database Search: Once an open reading frame or th...

Database Search: Once an open reading frame or the partial amino acid sequence has been pre-determined, the investigator compares sequence with others in the databases using a com

How many people carry the allele, Phenylketonuria is a severe form of menta...

Phenylketonuria is a severe form of mental disability caused by a homozygous recessive allele. The condition affects about 1 in 10,000 neborn Caucasians. Estimate the frequency of

protraction from hiv , Protraction from HIV  Under the following condi...

Protraction from HIV  Under the following conditions HIV is not transmitted 1) The secretions and body fluids like Saliva, Tears, Sweat, Faeces, and Urine have negligible HIV c

Drought-water stress and adaptations, Drought Drought refers to a condi...

Drought Drought refers to a condition of water shortage and it can result from many reasons. Frequently less than the normal rainfall is a common cause of drought. Less than 75

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