Nucleus of a cell: the largest organelle. Surrounded by a double membrane called the nuclear envelope consisting of nuclear pores. These pores regulate what goes in and out of the nucleus. A bulk of the interior of the nucleus is made up of nucleoplasm which contains chromatin and nucleoli.
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens agonist-mediated responses rather than provoking a biological response itself upon binding to a receptor.They are sometimes called blockers; examples include alpha blockers, beta blockers, and calcium channel blockers.n antagonist that binds to the active site of a receptor is said to be non-competitive if the bond between the active site and the antagonist is irreversible or nearly so.
Receptor antagonist responds when it itself is bound to the receptor biological, but it is a type of drug, and receptor ligands that do not delay the agonist-mediated response induce or block.ndogenous agonist for a particular receptor is a compound that forms in the body to naturally activated by binding with the receptor. For example, the endogenous agonist at serotonin receptors endogenous agonist of dopamine and serotonin receptors, some dopamine.