Question

a ligand can bind to a(n) ______ on the cell membrane
multiple choice
○ sodium ion
○ receptor
○ glycoprotein
○ atp pump
○ phospholipid

Explanation:

Ligands bind to receptors (proteins that receive chemical signals). Sodium ions are not binding targets for ligands in this context. Glycoproteins have various roles but ligand - receptor binding is specific to receptors. ATP pumps are for ion transport/energy - related functions, not ligand binding. Phospholipids form cell membranes, not ligand - binding sites. So the correct option is the one with "receptor".

Answer:

B. receptor (assuming the second option is labeled B; if the original labels were different, adjust the label but the text is "receptor")