Question

Intracellular receptors are found in the _____ or _____ of the cell, where they bond to chemical messengers that are _______ or very small, like nitric oxide.

Answer 1

Intracellular receptors are located in the cytoplasm or nucleus, where they bind to hydrophobic molecules or small messengers like nitric oxide that can cross the plasma membrane. These receptors can directly influence gene expression by binding to DNA and initiating transcription.

Step-by-step explanation:

Intracellular receptors are found in the cytoplasm or nucleus of the cell. They bond to chemical messengers that are either hydrophobic or very small, such as nitric oxide. Internal receptors, also known as cytoplasmic receptors, typically respond to hydrophobic ligand molecules that are able to travel across the plasma membrane.

When these hydrophobic molecules enter the cell, they bind to intracellular receptors and may cause a conformational change that exposes a DNA-binding site, allowing the ligand-receptor complex to move to the nucleus. There, it binds to specific DNA regions and promotes the initiation of transcription, directly influencing gene expression. An example of such a ligand is steroid hormones, which can penetrate the plasma membrane and bind to internal receptors due to their hydrophobic nature.