Compare ligand and receptor binding-site shape and chemistry, then trace how receptor binding starts signal transduction in cells with the matching receptor.
The complementarity of shapes and chemical properties allows molecules to bind to each other.
Describe, with examples, the types of molecule within cell-to-cell signalling systems that are complementary to each other.
a. signalling chemicals/ligands bind to receptors;
b. reference to specificity / the shape (and chemical properties) of the ligand-binding site match those of the ligand;
c. receptors can be in (either) the plasma membrane / intracellular / in the cytoplasm / or nucleus
OR
ligand can bind to transmembrane receptors/receptors in the plasma membrane or intracellular receptors;
d. only cells with a receptor to a signalling chemical will respond;
e. reference to signal transduction (initiated by signalling chemical-receptor binding);
f. example of signalling chemical;
Do not accept the role of glycoproteins in cell-cell recognition or ABO glycoproteins.
For b: do not accept "complementary" as this is part of the stem question.
For e. OWTTE
For e. the reference may include the pathway followed by a given example of a signalling chemical.
Appropriate example for (f):
- Neurotransmitters/named neurotransmitter
- any named hormone
- Cytokine
- Calcium ions