Why is the plasma membrane descibed as a semipermeable membrane? why are proteins required to augment the functions of hte phospholipid bilayer that forms the backbone of cell membranes? distinguish between the different types of molecular transport, why are they necessary, how do they enhance cellular functions, why are some cellualar processes free while others require the input of energy?

Why is the plasma membrane descibed as a semipermeable membrane? why are proteins required to augment the functions of hte phospholipid bilayer that forms the backbone of cell membranes? distinguish between the different types of molecular transport, why are they necessary, how do they enhance cellular functions, why are some cellualar processes free while others require the input of energy?

Biology: The Dynamic Science (MindTap Course List)

4th Edition

ISBN:9781305389892

Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Publisher:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter5: Membranes And Transport

Section: Chapter Questions

Problem 1TYK: In the fluid mosaic model: plasma membrane proteins orient their hydrophilic sides toward the...

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Similar questions

Why is it advantageous for the cell membrane to be fluid in nature?
Cells transporting substances across their membranes is essential. Choose TWO of the following types of cellular transport. ๏osmosis ๏active transport ๏facilitated diffusion ๏endocytosis / exocytosis (a)For each type of transport you choose, describe the transport process. Explain how the organization of cell membrane plays a role the movement of specific molecules across membrane. (b)Using the same transport types, identify a specific cell that utilizes that type of transit (i.e. one cell for each transport type, or two different cell examples), and detail a substance that is transferred. (c)A typical human lymphocyte has a radius of about 10 μm, while a typical bacterium (e.g., S. pneumoniae) has a radius of about 1 μm. Assuming that both cell types are perfectly spherical, compare and contrastthe transport mechanisms for each of these cells.
What Osmotic conditions would be favored by Plant and Animal cells? Why? Explain what is meant by the Fluid Mosaic Model of Membrane Structure. What are the various functions of membrane proteins? Explain the different forms of membrane transport: Passive, Facilitated, Active. Describe the bulk transport mechanisms of Endocytosis and Exocytosis.
1) You are studying a transport protein. It appears to bind temporarily to the molecule to be transported. During normal transport, no energy is expended. The addition of a particular molecule that closely resembles the normally transported molecule inhibits transport. An increase in the concentration of the normally transported molecule in the presence of a constant concentration of the inhibitor increases the rate of transport. What kind of transport is described? 2) What are peripheral membrane proteins?
Proteins may be bound to the exoplasmic or cytosolic face of the plasma membrane by way of covalently attached lipids. What are the three types of lipid anchors responsible for tethering proteins to the plasma-membrane bilayer? Which type is used by cell-surface proteins that face the external medium? By glycosylated proteoglycans?
How is active transport different from simple diffusion? Both active transport and simple diffusion transport molecules against the concentration gradient. In active transport, molecules are moved down the concentration gradient; on the B contrary, molecules to be transported in simple diffusion are moved against the concentration gradient. In active transport, molecules are transported with the aid of transport proteins; on the © other hand, molecules to be transported in simple diffusion do not need transport proteins. In active transport, molecules that are transported does not need metabolic energy; in contrast, molecules transported in simple diffusion need metabolic energy.
The uneven distribution of ions across the plasma membrane is regulated, in part, by transport proteins. The result is a net negative charge on the inside of the plasma membrane and a net positive charge on the outside of the plasma membrane. How doyou explain the net negative charge inside the plasma membrane when the predominant intracellular ion is K+?
The plasma membrane of E. coli is approximately 75% protein and 25% phospholipid by weight. It is known that the average membrane protein molecular weight is 50,000 Da and an average membrane phospholipid molecular weight is 750 Da. Calculate the number of membrane phospholipid molecules present per molecule of membrane protein. number of membrane phospholipid molecules: molecules Select the additional information that one would need to calculate the fraction of membrane surface covered by phospholipids. the average densities of a 50,000 Da protein and a 750 Da phospholipid the number of moles of protein and phospholipid in the membrane the surface area of the E. coli cell the average cross-sectional areas of a 50,000 Da protein and a 750 Da phospholipid in a bilayer
What is unique about plasma membrane? Why is it advantageous for the plasma membrane to be fluid in nature? How does the sodium-potassium pump contribute to the net negative charge of the interior of the cell? In medicine, why is it important to administer only isotonic intravenous solutions to patients? Example of isotonic IV fluids are normal saline and lactated Ringer’s solution. Potassium is a necessary nutrient in order to maintain the function of our cells. What would occur to a person that is deficient in potassium?
What are the four classifications of membrane proteins? How is each positioned with respect to the bilayer?
The fluid mosaic model of membrane structure has been very useful in explaining membrane behavior. However, the description of membrane as proteins floating in a phospholipid sea is oversimplified. Describe some components of membrane that are restricted in their lateral motion.
which of the following changes in the plasma membrane of a salmon is most likely to occur as it migrates to a much colder region of the Pacific Ocean? HInt: the fluidity of the salmon's plasma membranes must remain relatively constant during its migration. The percentage of integral membrane proteins in the plasma membrane would increase The percentage of unsaturated fatty acid tails in plasma membrane phospholipids would increase The percentage of unsaturated fatty acid tails in plasma membrane phospholipids would decrease The percentage of peripheral membrane proteins in the plasma membrane would increase