Receptor proteins are molecules inside a cell or on its surface on which ligands bind. A ligand is any substance (e.g. a hormone, drug, functional group) that binds specifically and reversibly to another chemical entity to form a large complex.
Receptor proteins found inside a cell are called internal receptors or intracellular receptors or cytoplasmic receptors.
They act as regulators of mRNA synthesis to mediate gene expression.
When a ligand binds to an internal receptor, the receptor changes in conformation and exposes on itself a site that can bind to DNA.
The receptor joined to the ligand moves into the nucleus where it binds to a specific site on the cell DNA. Once bound, it promotes the process of transcription where information is copied from DNA to mRNA
Why do plant cells have chloroplasts and cell walls?
the answer of this question is The cell wall surrounds the plasma membrane of plant cells and provides tensile strength and protection against mechanical and osmotic stress. and
this answer is for the cell wall
The correct answer is - <span>plankton populations die off and fishers are put out of work.
El Nino refers to very hot phases of ocean water, during which time plankton, and other oceanic organisms, quickly die off because of quite high temperatures. Without the plankton, there would be no food for the fish, which is why it is important for them to survive. If there are no plankton, there are no fish.
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Two countries that are on the opposite sides of the demographic transition, one being in the first faze, while the other in the fourth faze, will differ in pretty much everything.
The country in the first faze will have low economic development, bad infrastructure, the availability to the institutions will be limited to only some people. Most of the population will live in poverty, being on the verge of survival, and in very unhygienic conditions.
The country in the fourth faze will be the total opposite. It will be a highly developed country, with excellent infrastructure, the institutions are available for everyone. Most of the population will high income and be living in nice conditions.
In the country in the first faze, the birth rates will be high, but the death rates will be high as well, having a very low life expectancy too. In the country in the fourth faze, the birth rates will be very low, and the death rates will also be low, with the life expectancy being very high.