Receptor proteins.
Cell surface receptors recognize and bind to substances outside the cell. These receptors are usually proteins located on the cell membrane and play a crucial role in mediating communication between the cell and its external environment.
Enzyme
A target cell is a cell in the body that recognizes a hormone's chemical structure. It is a cell to which a hormone binds chemically.
cell-surface marker: identifies cell type receptor protein: recognizes and binds to substances outside the cell enzyme: assists chemical reactions inside the cell transport protein: helps substances move across the cell membrane source of information: "Biology principles and explorations" by Holt, Rinehart and Winston
A signaling molecule binds with a membrane protein
A signaling molecule binds with a membrane protein
Substances produced in a cell and exported outside of the cell would pass through the cell's plasma membrane via a process called exocytosis. Exocytosis involves the fusion of vesicles containing the substances with the plasma membrane, allowing the substances to be released outside the cell.
Active transport allows a cell to stockpile substances in far greater concentration that they occur outside the cell.
Hormone receptors on cell membranes recognize a hormone's chemical structure in the endocrine system. When the hormone binds to the receptor, a cell changes its behavior.
Substances outside a cell are transported into the cell by vesicles during endocytosis. This process involves the formation of a vesicle that engulfs the particles or molecules outside the cell, then fuses with the cell membrane to bring the contents into the cell.
lysosomes
A signaling molecule binds with a membrane protein