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When a cell eliminates large substances by releasing them from vesicles into the area outside the cell?
During exocytosis a vacuole containing material to be excreated from the cell moves to the plasma membrane and fuses with it. The vacuole membrane becomes part of the plasma membrane and the contents are released to the outside.
How do large molecules move across the membrane?
Integral membrane proteins enable ions and large polar molecules to pass through the membrane by passive or active transport. In facilitated transport, hydrophilic molecules bind to a “carrier” protein; this is a form of passive transport.
How do large molecules leave a cell?
Exocytosis is the process by which large molecules leave the cell. Vesicles from inside fuse with the plasma membrane and empty their contents. In endocytosis the plasma membrane forms a vesicle around the particle.
How do macromolecules enter and exit the cells?
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. Illustration of the two types of vesicle transport, exocytosis and endocytosis.
How does respiration occur in amoeba?
Respiration occurs as dissolved oxygen in the water diffuses across the cell membrane. In turn, carbon dioxide is eliminated from the amoeba by diffusion across the membrane into the surrounding water. Water is also able to cross the amoeba plasma membrane by osmosis.
How do amoeba reproduce by fission?
In mitosis, replicated DNA and organelles are divided between two daughter cells. These cells are genetically identical. Some amoeba also reproduce by multiple fission. In multiple fission, the amoeba secretes a three-layered wall of cells that harden around its body.
What is the food source of Amoeba?
The food source (bacterium, algae, etc.) is engulfed whole, digested, and the waste expelled. Amoebas commonly reproduce by binary fission, a process in which the cell divides into two identical cells.
What is the function of pseudopodia in amoeba?
In this process, the pseudopodia surround and engulf a bacterium or other food source. A food vacuole forms around the food particle as it is internalized by the amoeba. Organelles known as lysosomes fuse with the vacuole releasing digestive enzymes inside the vacuole.