Define the mechanism that hormones modify the biochemical activity of a target cell.
Hormones modify the biochemical activity of a target cell or tissue. Two basic mechanisms are involved.
- Fixed – Membrane – Receptor Mechanism
The fixed – membrane – receptor mechanism, applies to hormones that are proteins or amines. Because they are water – soluble and cannot diffuse across the plasma membrane, these hormones _initiate their response by means of specialized receptors on the plasma membrane of the target cell. Fig. 3.5.
- Mobile – Receptor Mechanism
The mobile – receptor mechanism, applies to steroid hormones. These hormones are lipid – soluble and diffuse easily into the cytoplasm, where they initiate their response by binding to cytoplasmic receptors. Fig. 3.6.
- What kind of hormones stimulate protein synthesis In a cell?
- Describe the biochemistry of hormones. How hormones help control biochemical reactions in the target cell?
- If a hormone Is the “first messenger” what is the “second messenger”? , Give a specific example.
- Control of Gene Expression in Eukaryotes
- CONTROL OF GENE EXPRESSION IN EUKARYOTES