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Cell or Plasma Membranes
Every cell has a cell membrane (plasma membrane) that separates the interior of the cell from the outside environment. One of the most important functions of this biological membrane is to protect the cell from outside threats by controlling the movement of substances in and out of the cell.
500 Questions
What is the advantage of the presence of on cell membranes?
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the membrane has a greater surface area for an increased rate of diffusion
Why are the two layers of phospholipids in a cell membrane arranged the way the way the are?
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What type of molecule is embedded in cell membranes?
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Proteins are often found embedded in the cell membrane. These proteins are called transmembrane or inter-membrane proteins.
Cholesterol molecules are also found embedded in the hydrophobic interior of the cell membrane in many species
Why is it important for the cell membrane to be fluid?
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The reason why the cell membrane requires a fluid consistency is to allow certain molecules to pass through. Fluidity is also important for phagocytosis to take place.
How does water move across the plasma membrane?
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Water moves across plasma membranes due to "Osmosis". Water may also move through the plasma membrane by flowing down a gradient from outside the cell into the inside of the cell since there is a less concentration of of water inside the cell (there are more things in the cell other than water such as proteins, hormones, and other substances).
How does the plasma membrane maintain homeostasis?
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The plasma membrane uses selective permeability to maintain homeostasis in a cell by eliminating wastes and taking in needed items.
What type of molecule has a carboxyl head and makes up cell membranes?
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Glycerol and fatty acids both have carboxyl heads, but i am not sure about their purpose yet.
What is the cell membrane that allows things to pass through?
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It is called semi-permeability, a series of biochemical structures and processes that Control The Ingress and Egress of bio-materials into and out of The Cell.
Are the living dead real?
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Quote from the link provided:
The origin of the concept of zombiism stems from Haitian Voodoo culture. The word zombie--in Haitian it is "zombi"--means "spirit of the dead." Voodoo folklore contends that Bokors, Voodoo priests that were concerned with the study and application of black magic, possessed the ability to resurrect the deceased through the administration of coup padre--coup padreis a powder that is issued orally, the primary ingredient of which is tetrodoxin, the deadly substance of the notoriously poisonous fou-fou (the puffer fish), or "porcupine fish." According to legend, "a zombi(e) is someone who has annoyed his or her family and community to the degree that they can no longer stand to live with this person. They respond by hiring a Bokor..to turn them into a zombi(e)."
Once they had been issued the coup padre, the subjects being prepared for their descent into zombidom would appear to die insofar as their heart rate would slow to a near stop, their breathing patterns would be greatly subdued and their body temperature would significantly decrease. The public, thinking that the person was dead, would bury him/ her as if they were a corpse. They would then be exhumed, still alive, by the Bokor and, although their physicality remained intact, their memory would be erased and they would be transformed into mindless drones. "Though still living, they remain under the Bokor's power until the Bokor dies."
So, yes, the living dead do exist, but they arent the brain-eating, rotting flesh kind we see in movies. They are poisoned humans who were once believed to be dead but were in actuality still alive.
What is net movement of substances across plasma membrane without additional energy?
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Diffusion. With the need of energy, it would be called active transport.
Oxygen crosses the plasma membrane by?
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Simple diffusion process, i.e. from high pressure to low pressure
Does prokaryotic or eukaryotic cells contains plasma membrane?
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Both eukaryotic cells and prokaryotic cells have a plasma membrane.
Does human cells have a cell membrane?
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Animal (including human) cells have cell membranes, and so do plant cells. Animal cells do not have a cell wall, however.
What are the irregular in-folding of the plasma membrane of bacterial cells?
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Ribosomes
What is the Location of plasma cells?
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Differentiated B-Cells, or Plasma cells, along with a variety of other lymphocytes are most commonly found in the lamina propria, or subendothelial layer of the tissues which are most readily accessible to foreign antigens, i.e. gastrointestinal tract, respiratory passages, and urogenital tract.
What effect does organic solutes have on the permeability of beetroot cell membrane?
Asked by Wiki User
The rate of osmosis is dependent on the gradient between the solute concentrations, the permeability of the membrane and of course, the temperature of the solution. Temperature affects the rate because the warmer the temperature the faster the diffusion will take place.
Why a colony of cell does not get tissue level of organization?
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a tissue means similar cells performing similar function whereas colony means cell performing different functions.
What would happen if there was damage to the plasma membrane?
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Plasma membrane defines the boundary of the cell and regulates the flow of material into and out of the cell. Ruptured plasma membrane generally heals within no time but if rupturing does not heal, the cell contents will spill over and cell is killed.
What are passive transport active transport and endocytosis?
Asked by Wiki User
These are three different ways that cells have to get things in and out of the cell. Passive transport is movement without the use of energy, active transport requires energy.
Active transport requires energy since the molecules are going toward a region that has a higher concentration of that molecule. The cell is 'stuffing' more into itself.
Endocytosis means to 'take into the cell'. Usually this a larger molecule and cell must wrap part of itself around the molecule and then can bring it inside. This is a type of phagocytosis (cell eating).
This requires energy as well.
Which molecules have heads and tails in the plasma membrane?
Asked by Wiki User
phospholipid molecules....they have polar hydrophillic head(like water-as there is phosphate group attached on it..phosphate group has oxygen molecules with all their pairs of unshared electrons.) and hydrophobic tails(scare water)
Why is the plasma membrane selectively permeable?
Asked by Wiki User
The plasma membrane is selectively permeable because it needs to allow certain things in and certain things out.
The plasma membrane is a selectively permeable membrane as it allows the entry and exit of some selected substances only.
