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What does a cell "eat"? Is it possible for objects larger than a small molecule to be engulfed by a cell? Of course it is. This image depicts a cancer cell being attacked by a cell of the immune system. Cells of the immune system consistently destroy pathogens by essentially "eating" them. Vesicle TransportSome molecules or particles are just too large to pass through the plasma membrane or to move through a transport protein. So cells use two other active transport processes to move these macromolecules (large molecules) into or out of the cell. Vesicles or other bodies in the cytoplasm move macromolecules or large particles across the plasma membrane. There are two types of vesicle transport, endocytosis and exocytosis (illustrated in Figure below). Both processes are active transport processes, requiring energy.
Illustration of the two types of vesicle transport, exocytosis and endocytosis. Endocytosis and ExocytosisEndocytosis is the process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane. The membrane folds over the substance and it becomes completely enclosed by the membrane. At this point a membrane-bound sac, or vesicle, pinches off and moves the substance into the cytosol. There are two main kinds of endocytosis:
Transmission electron microscope image of brain tissue that shows pinocytotic vesicles. Pinocytosis is a type of endocytosis. Exocytosis describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell, as shown in Figure below. Exocytosis occurs when a cell produces substances for export, such as a protein, or when the cell is getting rid of a waste product or a toxin. Newly made membrane proteins and membrane lipids are moved on top the plasma membrane by exocytosis. For a detailed animation of cellular secretion, see http://vcell.ndsu.edu/animations/constitutivesecretion/first.htm. Illustration of an axon releasing dopamine by exocytosis. Summary
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Problem A It forms intracellular vesicles from inward folding of the plasma membrane. B It requires fusion of vesicles with the plasma membrane. C It secretes large molecules out of the cell. D It is responsible for removing large waste particles that cannot be recycled by the cell. Next question Related Videos Related Practice BioFlix: Exocytosis and Endocytosis by Pearson 13 views Animation: Exocytosis and Endocytosis by Pearson 17 views Endocytosis, phagocytosis, and pinocytosis | Biology | Khan Academy by Khan Academy 85 views Endocytosis, exocytosis, phagocytosis, and pinocytosis explained! by DrDiclonius 98 views Endocytosis & Exocytosis by sci-ology 115 views Endocytosis and Exocytosis by Jason Amores Sumpter 230 views A Level Biology Revision "Endocytosis and Exocytosis OCR / Edexcel" by Freesciencelessons 109 views Amoeba eats paramecia ( Amoeba's lunch ) [ Amoeba Endocytosis / Phagocytosis Part 1 ] đź‘Ś by Morris Kemp 108 views Cell Membrane Transport - Transport Across A Membrane - How Do Things Move Across A Cell Membrane by Whats Up Dude 49 views Endocytosis Allows Entry to the Cell by Jason Amores Sumpter 171 views 1 Endocytosis and Exocytosis Example 1 by Jason Amores Sumpter 149 views Exocytosis Allows Exiting from the Cell by Jason Amores Sumpter 176 views 1 Which of the following is a correct statement regarding exocytosis and endocytosis?The correct answer is that a- Endocytosis and exocytosis involve active transport. Both endocytosis and exocytosis require the use of ATP for the cell to enclose the particles being brought in, or to move the vesicle out of the cell, this makes both of these processes active transport.
Which of the following is a correct difference between exocytosis and endocytosis?Endocytosis vs exocytosis
Endocytosis involves cells taking in substances from outside the cell by engulfing them in a vesicle derived from the cell membrane. Exocytosis is where cells shift materials, such as waste products, from inside the cell to the extracellular space.
What is true for both endocytosis and exocytosis?Exocytosis describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell. Both endocytosis and exocytosis are active transport processes.
Which statement about exocytosis is correct?Exocytosis is the exportation of materials inside the cell to the outer environment. It involves the budding of membrane-bound vesicles that often originate from the endoplasmic reticulum off of the plasma membrane. A is the correct answer.
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