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

Initiation codon, Initiation Codon is the codon at which the translation o...

Initiation Codon is the codon at which the translation of a polypeptide chain is initiated. This is generally the first AUG triplet in the mRNA molecule from 5' end, where the rib

Excretion., organisms and their excretory organelles

organisms and their excretory organelles

Define premotor cortex located in the frontal lobes, Q. Define Premotor Cor...

Q. Define Premotor Cortex Located in the frontal lobes? Premotor Cortex - Involved in control of more complex, learned motor skills like writing, driving, etc. Broca's area or

What are the three parts of a dna nucleotide, What are the three parts of a...

What are the three parts of a DNA nucleotide, and how are they connected to each other? The three types are a deoxyribose sugar, a phosphate group, and a nitrogenous base. The

Vasodilatation from the time of injury, The blood vessels surrounding an ac...

The blood vessels surrounding an acutely inflamed site usually represent progressive vasodilatation from the time of injury.

Phylum, general charactristics of phylum protozoa

general charactristics of phylum protozoa

Anti lipid drugs-peri operative problems, Anti Lipid Drugs :  The current ...

Anti Lipid Drugs :  The current thinking is that it is very important to keep lipid levels low. It helps in preventing atherosclerotic changes in venous grafts and the long-term p

Scentific american article suggests some improvements, The human skeleton h...

The human skeleton has evolved from that of four-legged animals. Unfortunately, the adaptation is far from perfect; thus, our upright posture causes problems like backage and the k

Prokaryotic cell, whatis a prokaryotic cell? explain its structure and desc...

whatis a prokaryotic cell? explain its structure and description with images

Advantages of the dsme, Following are the advantages of the DSME: It enable...

Following are the advantages of the DSME: It enables the patient to 1. Accept the disease. 2. Gain knowledge about disease, its prevention, treatment and management. 3.

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