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

Insulin and its functions, People with Type 1 DM produce no insulin. People...

People with Type 1 DM produce no insulin. People with Type 2 DM do not always produce enough insulin. Insulin is used medically to treat some forms of diabetes mellitus. Patients w

When manifested in homozygosity in the offspring?, Why can it be said that ...

Why can it be said that a recessive allele can remain hidden in the phenotype of an individual and revealed only when manifested in homozygosity in the offspring? A recessive a

Digestion, explain digestion in protozoans

explain digestion in protozoans

Respiration, define respiration in diffrent types of animals

define respiration in diffrent types of animals

Pheromones serving functions other than reproduction, Pheromones Serving Fu...

Pheromones Serving Functions Other than Reproduction Besides sexual responses as described above pheromones mediate several other types of behaviour. Alarm pheromones have bee

Where in eukaryotic cells does mrna synthesis occur, Where in eukaryotic ce...

Where in eukaryotic cells does mRNA synthesis occur? To where do these molecules migrate? Messenger RNA molecules are synthesized within the nucleus, pass by pores of the nucle

Forms of ribosomes, FORM S OF RIBOSOMES (1 )      Bound form - Atta...

FORM S OF RIBOSOMES (1 )      Bound form - Attached to ER. Protein synthesis for secretion purpose occurs on bound ribosomes. (2 )      Free Ribosomes - Occur freely

Explain microbiological apparatus and equipments, Explain Microbiological A...

Explain Microbiological Apparatus and Equipments? It provides an orientation to the various basic equipments, i.e., instruments, tools, glassware and miscellaneous items used i

Competition - processes in succession , Competition - Processes in Successi...

Competition - Processes in Succession The aggregation of individuals in an area leads to inter specific and intra specific competition. The competition is usually for

Define growth studies for studying nutrient requirement, Define Growth Stud...

Define Growth Studies for studying Nutrient Requirement? Nutrient requirements of infants and young children are estimated by studying the rate of growth of healthy children an

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