Action of steroid hormone

How steroid hormones enter the cell

Steroid hormones are lipid soluble. What implications does this have in terms of how they enter cells? - They are able to easily diffuse across the cell membrane and do not require the aid of receptors.

How do hormones work?

Hormones influence the growth and development of organisms. For example hormones determine whether individuals become male or female. Many hormones are steroids. Steroids are a class of lipids. All steroids share a carbon skeleton composed of four fused rings. Hormones are compounds used for long distance signaling in both plants and animals. In animals, specialized cells produce hormones and release them into the circulatory system. Hormones travel to target cells in other parts of the body and cause a variety of changes in the target areas. Changes caused by hormones include changes in gene expression in target cells as well as Steroid hormones are soluble in lipids and can easily pass through cellular and nuclear membranes. In contrast, many other hormones are water soluble. Steroid hormones typically act by affecting gene expression while water-soluble hormones usually act by causing changes in biological processes in the cytoplasm of cells

The targets of steriod hormones tend to be:

Protien receptors, either in tbe cytoplasm or within the nucleus.

Events after steroid binding

The process that is first initiated after the steroid hormone binds to the receptor within the nucleus of a cell is transcription of specific genes

Speed of steroid hormones

steroid hormones are slower to function then peptide hormones because steroid hormones do not use second messengers, but instead, must wait for gene expression pathways to be activated.

Mechanism of Steroid Hormone Action

1. Steroid hormones bind to protein receptors in the cytoplasm or nucleus of the target cell. 2. The steroid hormone-receptor complex: The steroid hormone-receptor complex binds to hormone response elements in DNA. 3. The mode of action of steroid hormones involves stimulation of mRNA transcription. 4.