acts as catalysts
When a receptor protein acts as an enzyme, the receptor protein activates a second messenger that acts as a signal molecule within the cell. Resources: HOLT Biology Textbook - 9th grade edition Chapter 4, Cells and Their Environment.
Receptors detect a signal molecule and perform an action in response.
The type of molecule that is an enzyme is a protein molecule.
I protein is something that is made up of Amino Acids and usually has some sort of function in a cell such as being a membrane receptor or an enzyme.
When protein membrane receptors are activated, they usually undergo a conformational change, which triggers a downstream signaling cascade. This cascade can involve the activation of intracellular proteins or the production of second messengers, leading to a variety of cellular responses such as gene transcription, enzyme activation, or changes in cellular metabolism. Ultimately, the activation of protein membrane receptors initiates a cellular response to the signaling molecule that bound to the receptor.
The four main types of proteins found in a cell membrane are integral proteins, peripheral proteins, glycoproteins, and channel proteins. Integral proteins are embedded within the lipid bilayer, while peripheral proteins are attached to the surface of the membrane. Glycoproteins have carbohydrate chains attached to them, and channel proteins help facilitate the movement of specific substances across the membrane.
Both enzymes and receptors have specific sites for the substrates to bind. The receptor causes a response beyond the cell membrane and the enzyme facilitates a chemical change in the substrate. Enzymes can be membrane bound or free floating. Receptors are usually membrane proteins
haemoglobin
Protein.
Is a molecule upon which an enzyme acts. e.g. hydrogen peroxide is the substrate for the enzyme catalase
the strarch molecule binds to an enzyme
it determines how the molecule functions