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In all cells, the cell membrane acts as a combination of brick wall, window, and security guard.
The cell membrane is to a considerable extent made up of a double sheet of fatty molecules (the phospholipid bilayer) which is impermeable to most substances. Only small, uncharged molecules such as those of oxygen, carbon dioxide, and water can cross this bilayer.
There are apertures in the cell membrane, each of which is formed by one or more protein molecules. These allow across the membrane substances that cannot cross the phospholipid bilayer.
The proteins embedded in the phospholipid bilayer are selective. Through such features as channel (pore) size, charge, and three-dimensional shape, these transport proteins (channel and carrier proteins) regulate which substances enter and leave the cell. An important function of the cell membrane is therefore to regulate the passage of atoms, molecules, and ions in and out of the cell. This in turn maintains a stable chemical environment within the cell, which is important, for example, for keeping conditions optimal for intracellular enzymes.
Carrier proteins are capable of pumping substances up (against) their concentration gradient, in a process called active transport.
The cell membrane has further functions. Protein receptor molecules recognize specific hormones and growth factors, and thus determine whether a cell will respond to a particular signal molecule. And chemical compounds attached to the outside of the cell membrane play a role in adhesion(keeping cells together in a tissue). Furthermore, movements of the cytoskeleton just interior to the cell membrane cause changes to the shape of the membrane, for example in endocytosis and exocytosis.
What else can I help you with?
Can you give me a sentence using the word cell membrane?
A plant cell has a cell membrane and a cell wall.
Another name for plasma membrane?
A cell membrane is also known as a plasma membrane or cytoplasmic membrane. The cell membrane separates the interior of a cell from its outside environment. The main function of a cell membrane is to protect the cell from its surroundings.
What is the thin flexible membrane around all cells?
the cell membrane is as flexible barrier outside of the cell.
What purpose would a cell use a lipid monomer?
The purpose a cell would have to use a lipid monomer would be for use for the cell membrane. The cell membrane protects the contents of the cell.
What is the outer boundary of a cheek cell called?
cell surface membrane cell surface membrane
What does the cell membrane use for energy?
The cell membrane does not use energy.
How I can use cell membrane in a sentences?
cell membrane is the most outer part of a cell. cell membrane is very big in surface.
How do you use membrane in a sentence?
A membrane is apart of a animal or plant cell.
Can you give me a sentence using the word cell membrane?
A plant cell has a cell membrane and a cell wall.
What is cell membrane pumps?
cell membrane pumps use energy to force molecules in a direction opposite of natural.
What is use of the plasma membrane?
plasma membrane is the outer most covering of the cell,...
terms use for the structure that separates the cell from its surrondings?
Cell membrane
What specialized structures do a prokaryotic cell use to maintain homeostasis?
cell membrane
What Controls what moves in and out of the cell?
Cell membrane
Another name for plasma membrane?
A cell membrane is also known as a plasma membrane or cytoplasmic membrane. The cell membrane separates the interior of a cell from its outside environment. The main function of a cell membrane is to protect the cell from its surroundings.
What is the thin flexible membrane around all cells?
the cell membrane is as flexible barrier outside of the cell.
What does a plant or animal cell use to anchor guide or group its organelles?
The animals outer layer is called the cell membrane. The plants cell membrane still exists, but it has another layer surrounding the membrane called the cell wall.
