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a.
To determine:
The differences in the diffusion rates of chemicals A and B.
Introduction:
The membrane that is present below the cell wall and glycocalyx is a cytoplasmic membrane. It is also known as plasma membrane or cell membrane. The structure of the cytoplasmic membrane is referred to the phospholipid bilayer and the membrane of bacteria is composed of integral proteins. Peripheral proteins are loosely attached to the membrane on one or another side which acts as enzymes, receptors, recognition proteins, and carriers.
Cell membrane controls the movement of substances inside and outside of the cell with the main function of protecting the cell for the surroundings. It also provides shape to the cell and involves in different cellular processes such as cell signaling, cell adhesion, and ion conductivity.
b.
To explain:
The reason that diffusion rate of chemical A taper off.
Introduction:
The membrane that is present below the cell wall and glycocalyx is a cytoplasmic membrane. It is also known as plasma membrane or cell membrane. The structure of the cytoplasmic membrane is referred to the phospholipid bilayer and the membrane of bacteria is composed of integral proteins. Peripheral proteins are loosely attached to the membrane on one or another side which acts as enzymes, receptors, recognition proteins, and carriers.
Cell membrane controls the movement of substances inside and outside of the cell with the main function of protecting the cell for the surroundings. It also provides shape to the cell and involves in different cellular processes such as cell signaling, cell adhesion, and ion conductivity.
c.
To determine:
The way in which the cell increase the diffusion rate of chemical A.
Introduction:
The membrane that is present below the cell wall and glycocalyx is a cytoplasmic membrane. It is also known as plasma membrane or cell membrane. The structure of the cytoplasmic membrane is referred to the phospholipid bilayer and the membrane of bacteria is composed of integral proteins. Peripheral proteins are loosely attached to the membrane on one or another side which acts as enzymes, receptors, recognition proteins, and carriers.
Cell membrane controls the movement of substances inside and outside of the cell with the main function of protecting the cell for the surroundings. It also provides shape to the cell and involves in different cellular processes such as cell signaling, cell adhesion, and ion conductivity.
d.
To determine:
The way in which the cell increase the diffusion rate of chemical B.
Introduction:
The membrane that is present below the cell wall and glycocalyx is a cytoplasmic membrane. It is also known as plasma membrane or cell membrane. The structure of the cytoplasmic membrane is referred to the phospholipid bilayer and the membrane of bacteria is composed of integral proteins. Peripheral proteins are loosely attached to the membrane on one or another side which acts as enzymes, receptors, recognition proteins, and carriers.
Cell membrane controls the movement of substances inside and outside of the cell with the main function of protecting the cell for the surroundings. It also provides shape to the cell and involves in different cellular processes such as cell signaling, cell adhesion, and ion conductivity.
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Chapter 3 Solutions
Microbiology With Diseases By Taxonomy Plus Mastering Microbiology With Pearson Etext -- Access Card Package (6th Edition)
- Match the definitions with the words: Direct Diffusion, Facilitated Transport, Active Transport a) passive movement of molecules through a protein channel, down the solute's concentration gradient b) using a vesicle to move many molecules into a cell c) movement of molecules through a protein transporter, requires ATP, against the solute's concentration gradientarrow_forwardThis graph shows facilitated diffusion of a compound across a cytoplasmic membrane and into a cell. As the external concentration of the compound is increased, the rate of uptake increases until it reaches a point where it slows and then begins to plateau. This is not the case with passive diffusion, where the rate of uptake continually increases as the solute concentration increases. Why does the rate of uptake slow and then eventually plateau with facilitated diffusion?arrow_forwardPropose an experiment that would distinguish pore-mediated diffusion (e.g.,by gramicidin) from carrier-mediated diffusion (e.g., by valinomycin).arrow_forward
- Active transport pumps are used to move sodium ions across the membranes of gill cells in freshwater fish species. Which of the following statements about the pumps is accurate?Explain. a) There are specific binding sites for sodium ions on the pump b) They require osmosis to carry the sodium ions into the cell c) This is an example of passive diffusion and ATP is required d) Their lipid based structure allows it to embed in the cell membranearrow_forwardA) Consider membrane filtration. What is concentration polarization and why does it occur? B) What are the important parameters that affect the diffusivity in/across membranes and what do The they mean physically? C) Consider the Krogh Cylinder model. What is the physical meaning of the critical radiusand why does it occur?arrow_forwardCholera is caused by a toxin produced by the bacterium Vibrio cholerae. Ultimately, the toxin leads to the activation of ion channels by Protein Kinase A (PKA), indirectly causing water to leave the cell (following ions out of the cell). This loss of electrolytes and water from intestinal cells into the intestinal lumen, produces the watery diarrhea characteristic of a V.cholera infection. Would you expect lower or higher levels of PKA in cells exposed to the cholera toxin? If you were to measure CAMP levels in these cells, what would you expect to find? Why? How might the cholera toxin modify G-proteins to result in these cAMP levels?arrow_forward
- 1) Cystic fibrosis is due to a defect in a pump of the cell membrane. Discuss the causes and treatments of this disease.arrow_forwardDescribe facilitated diffusion, primary and secondary active transport, and group translocation in terms of their distinctive characteristics and mechanisms. What advantage does a bacterium gain by using active transport rather than facilitated diffusion?arrow_forwardBoth active and passive transports can be subdivided further. Distinguish between the different pairs of terms below: a) simple diffusion vs. facilitated difussion b) Facilitated diffusion vs. active transport c) channel protein vs. carrier protein d) simple diffusion vs. osmosis e) Uniporter vs. symporter vs. antiporterarrow_forward
- The African swine fever virus has two membrane bilayers around the outside of the virus. The outer layer is from the host cell that the virus infects—it takes part of the host membrane with it as it leaves the cell. This membrane then fuses with the next cell the virus infects, and it is known that cholesterol is required in the membrane of the cell being infected in order for the virus to successfully infect the cell. Which of the following is the best explanation for why cholesterol would be required in the membrane of the cell the virus is infecting? Explain your choice in 25 words or less. Viral proteins may not have the correct conformation if the host membrane is less fluid due to lower cholesterol levels The cholesterol forms a channel through the membrane that allows the virus to enter the cell, and without cholesterol the virus cannot enter the cell The cholesterol disrupts a small portion of the hydrophobic core of the membrane to allow the virus to enter the cell, and…arrow_forward25.arrow_forwardFor a lab on diffusion and osmosis, where a egg yolk was placed in a cup water the following question asks Consider a scenario in which the size of an egg yolk remains unchanged after in water soaking for an hour. What are two possible explanations as to why this occurs? What would two reasons be for the yolk to be unchanged after a hour in water?arrow_forward
