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 are similarities between proteins, What are some similarities between ...

What are some similarities between proteins, carbohydrates, and nucleic acids?

Explain the nutritional and functional role of iron, Minerals :- Iron ...

Minerals :- Iron Food Source      Cereals, legumes, meat contamination from iron utensils and soil Nutritional Functional role Essential nutrient: Deficiency lead

Find the modalities in stress testing, Q. Find the Modalities in stress tes...

Q. Find the Modalities in stress testing? In addition to electrocardiographic stress testing, there are various newer modalities that can be very useful in the determination o

Precautions by dangers of working in labs with animals, The dangers of work...

The dangers of working in labs with animals will be minimised if the following precautions are taken: 1. Wash all dissection instruments in disinfectant after use. 2. Never

Spermatogenesis, Spermatogenesis: In the mature male functional sper...

Spermatogenesis: In the mature male functional sperm cells are produced within the seminiferous tubules of the testes. Around the periphery of the seminiferous tubules are l

Explain the flower in diversity of life, Explain the Flower in diversity of...

Explain the Flower in diversity of life? In order for plants to evolve from an aquatic existence to a terrestrial existence, specific adaptations in their basic modes of reprod

Peroxisomes and glyoxysomes, PEROXISOMES AND GLYOXYSOMES Certain small ...

PEROXISOMES AND GLYOXYSOMES Certain small ovoid  unit membrane bound  sac like  cytoplasmic  organelles, resembling  lysosomes in size  and appearance  were  isolated  from var

Explain indifferences in ionic composition, Indifferences in ionic composit...

Indifferences in ionic composition Answer A. across membranes can be created through the action of ATP driven pumps as long as number of negative and positive ions on remain equal

Immediate post-operative care to a cardiac patient, Immediate Post-operativ...

Immediate Post-operative Care The patient is accompanied to the ICU by a surgeon, anesthetist and the nurse who assisted for the surgery with portable ventilator and ECG

Explain gelation - function of proteins, Explain Gelation - Function of pro...

Explain Gelation - Function of proteins Gelation  refers to the process where denatured molecules aggregate to form an ordered protein network. Proteins  can form a well-order

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