Receptors
• Receptors- target cell proteins either on the surface of the cell or inside the cell which responds
to stimuli by binding of a chemical messenger such as Neurotransmitters or Hormones.
• In receptors there are specific binding sites for specific chemical messengers, these chemical
messengers are known as “ligand”, which activate the receptor by changing its tertiary
structure.
• Then a process known as “Signal Transduction” occurs, it is when a receptor is activated
initiating internal processes inside the cell leading to a cell's response.
TYPES OF RECEPTORS
➢ Now that we know, receptors are proteins or glycoproteins located inside the cell's
(cytosol or in the nucleus) and on the cell's plasma membrane.
➢ In the surface of the plasma membrane lies huge amount of water-soluble messengers,
that cannot easily penetrate the plasma membrane.
- For Instance, Peptide Hormones (FSH, LH…) as example: since the membrane is
made of a phospholipid bilayer ,these hormones are water-soluble and too big
so they cannot move through this membrane, the way for these hormones to
penetrate the cell is by binding to a certain types of receptors on the membrane
so that it can exerts its effect on the cell. ☺
➢ So small number of lipid-soluble messengers can penetrate through the phospholipid
bilayer
- For instance, Steroid hormones such as oestrogen, Cortisol, Testosterone and
so on.
Therefore Receptors are categorized into two(2)
1. Plasma Membrane Receptors (Cell surface receptors)
2. Intracellular Receptors
• Receptors- target cell proteins either on the surface of the cell or inside the cell which responds
to stimuli by binding of a chemical messenger such as Neurotransmitters or Hormones.
• In receptors there are specific binding sites for specific chemical messengers, these chemical
messengers are known as “ligand”, which activate the receptor by changing its tertiary
structure.
• Then a process known as “Signal Transduction” occurs, it is when a receptor is activated
initiating internal processes inside the cell leading to a cell's response.
TYPES OF RECEPTORS
➢ Now that we know, receptors are proteins or glycoproteins located inside the cell's
(cytosol or in the nucleus) and on the cell's plasma membrane.
➢ In the surface of the plasma membrane lies huge amount of water-soluble messengers,
that cannot easily penetrate the plasma membrane.
- For Instance, Peptide Hormones (FSH, LH…) as example: since the membrane is
made of a phospholipid bilayer ,these hormones are water-soluble and too big
so they cannot move through this membrane, the way for these hormones to
penetrate the cell is by binding to a certain types of receptors on the membrane
so that it can exerts its effect on the cell. ☺
➢ So small number of lipid-soluble messengers can penetrate through the phospholipid
bilayer
- For instance, Steroid hormones such as oestrogen, Cortisol, Testosterone and
so on.
Therefore Receptors are categorized into two(2)
1. Plasma Membrane Receptors (Cell surface receptors)
2. Intracellular Receptors
