Receptor proteins.
Enzyme
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.
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.
lysosomes
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.
Exocytosis is the process by which large substances are moved out of the cell. This involves the fusion of vesicles containing the substances with the cell membrane, releasing the substances outside the cell.