non-enzymatic proteins

Question 1

protein roles in binding

Answer 1

non-enzymatic proteins can bind various biomolecules specifically and tightly
membrane receptors bind or receive signaling molecules (ligands) which lead to chemical responses (ex: insulin receptor)
ion channels can allow ions to enter or exit a cell

Question 2

protein roles in immune system

Answer 2

non-enzymatic proteins can act as
antibodies, which are proteins of the adaptive immune system that find foreign antigens and target them for destruction

Question 3

protein roles in movement

Answer 3

myosin is responsible for forces exerted by contracting muscles
transport (ex: hemoglobin)
kinesin/dynein are motor proteins responsible for intracellular transport
dynein also plays a role in the motility of cilia