Characteristics of membrane protein:.
1. Membrane proteins transfer genetic information to the cytoplasm.
2. Membrane proteins act as receptors to molecules like hormones.
3. Membrane proteins form junctions between cells.
4. Membrane proteins serve as enzymes.

Membrane proteins act as receptors to molecules like hormones.

Explanation:

Membrane proteins are proteins that are closely associated with a cell membrane. On the cell membrane, they could act as receptors to molecules like hormones that need to be transported across the hydrophobic lipid bilayer.

A good example of membrane proteins is sodium channel, that acts as receptor to neurotransmitters.

the farther away the object is from the central star (the sun) it's gravitainal pull on the object is weaker when it is farther

explanation:

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products