IB Biology HL 2.1.1 Receptors as proteins Question Bank

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;

Marking guidance:

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

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