Welcome to this lesson on steroids and non-steroid hormones. In this lesson today, you are going to be learning about the characteristics of both steroid and non-steroid hormones. Specifically, you will look at:
Hormones are chemicals made within the body that will interact with specific types of cells, signaling the cell's activity to change in some way depending on what the hormone is and what the cell type is. Cell receptors are specific to the hormones they interact with and certain types of hormones can only affect certain types of cells. This means that not every hormone affects every type of cell because not all cells will possess their receptors.
Steroid hormones are lipids that are made from cholesterol and they're produced in the adrenal glands and reproductive glands. Because steroid hormones are lipids made from cholesterol, the are lipid soluble. This means is they can move through the plasma membrane easily and because they're allowed to move through the plasma membrane, they will bind with receptors on the nucleus.
Steroid hormones will bind to receptors on the nucleus and this will allow them to affect the behavior of the DNA. They can turn genes and DNA on or off; this controls protein-making mechanisms and can directly affect the target cell's function.
Examples of steroid hormones are estrogen and testosterone. Estrogen and testosterone are examples of steroid hormones because they're produced within reproductive glands and are lipid-based, made from cholesterol.
Non-steroid hormones are the other class of hormones but are different in their structure and how they interact with their target cells. Non-steroid hormones are derived from proteins and because of this they are water soluble and cannot enter the cell. Non-steroid hormones cannot pass through the cell's plasma membrane because they're water soluble. In this case, non-steroid hormones bind to receptors on the target cell's plasma membrane.
Remember, steroid hormones bind to receptors on the nucleus and non-steroid hormones are going to bind to receptors on the target cell's plasma membrane. Since non-steroid hormones aren't able to pass through the plasma membrane they will activate what are called second messengers.
Secondary messengers relay information to the interior of the cell. when non-steroid hormones bind with their receptors on the plasma membrane. The secondary messenger will not be activated until the non-steroid hormone binds with its receptor. This is necessary because non-steroid hormones cannot enter cells and this is how they change what is happening on the inside without actually entering.
So, this lesson has been an overview of steroid and non-steroid hormones and secondary messengers.
Keep up the learning and have a great day!
Source: THIS WORK IS ADAPTED FROM SOPHIA AUTHOR AMANDA SODERLIND
Hormones that have a cholesterol backbone and are not soluble in water due to their lipid structure; steroid hormones are transported through the blood attached to carrier proteins. Steroid hormones penetrate the cell membrane and interact with nuclear receptors that affect DNA transcription.
A class of hormones that are primarily derived from proteins and are water soluble due to their polar nature; steroid hormones are transported freely through the blood. Non-steroid hormones interact with receptors on the cell membrane and activate secondary messenger systems that carry out their effects within the cell.
A group of signaling molecules located near a hormone receptor on the inside of the cell; when a non-steroid hormone binds to its receptor it activates secondary messenger systems that carry out specific effects inside of the cell. Non-steroid hormones rely on secondary messenger signaling molecules because they are unable to penetrate the cell membrane and get into the cell.