When would a cell use exocytosis?
Exocytosis occurs when a vesicle fuses with the plasma membrane, allowing its contents to be released outside the cell. Exocytosis serves the following purposes: Removing toxins or waste products from the cell’s interior: Cells create waste or toxins that must be removed from the cell to maintain homeostasis.
What are the two kinds of bulk transport?
The movement of macromolecules such as proteins or polysaccharides into or out of the cell is called bulk transport. There are two types of bulk transport, exocytosis and endocytosis, and both require the expenditure of energy (ATP).
What process is the opposite of exocytosis?
While exocytosis is a form of active transport that moves substances and materials from a cell’s interior to the exterior of the cell, endocytosis, is the mirror opposite. In endocytosis, substances and materials that are outside of a cell are transported into the interior of the cell.
What is an example of bulk transport?
Substances that can move via bulk transport are like hormones, polysaccharides, etc. An example of this is the engulfing of pathogens by phagocytes (endocytosis), then the release of the hydrolysed pieces of the pathogen outside the cell by exocytosis.
Is phagocytosis endocytosis or exocytosis?
Phagocytosis (literally, “cell eating”) is a form of endocytosis in which large particles, such as cells or cellular debris, are transported into the cell.
What are cell surface receptors?
Cell surface receptors are found on the outer surface of the cell membrane and bind to the extracellular signaling molecule (ligand) to undergo signal transduction.
What happens if a cell doesn’t have the correct receptor?
In some cases, if a cell doesn’t have the correct receptor for a particular substance, then that substance won’t affect the cell. For example, leptin is the hormone that causes you to feel full and satiated following a big meal.
How do cell receptors work?
This article explains how cell receptors work, their role in the human body, and their significance. Here’s one way to think of this: a receptor is like a lock, while the substance binding to it is the key to that lock.
Why don’t surface receptors diffuse through the plasma membrane?
This is often because these ligands are hydrophilic or large, making them unable to diffuse through the plasma membrane. There are three main types of cell surface receptors: ion channel receptors, G-protein coupled receptors (GPCRs) and enzyme-linked receptors.