1. Which of the following would increase the rate at which integral membrane proteins move from...

1. Which of the following would increase the rate at which integral membrane proteins move from one end of the cell to the other?

	A.	An increase in temperature
	B.	An increase in pH
	C.	A decrease in the number of double bonds in the fatty acid tails of the membrane phospholipids
	D.	An increase in the length of the fatty acid tails of the membrane phospholipids

2. Some bacteria produce toxins that allow them to pass across the epithelial layer in the lining of the gut. Which type of cell-to-cell junction do these toxins affect?

	A.	Tight junctions
	B.	Plasmodesmata
	C.	Adhesive junctions (e.g. desomosomes)
	D.	Gap junctions

Solutions

Expert Solution

Answer: A. An increase in temperature

Explanation:

When temperature is increased, the kinetic energy and hence fluidity of the membrane increases. As a result, the integral protein can easily swim in the lipid bilayer of the membrane and reach the other end of the cell.

An increase in pH has no significant effect on cell membrane fluidity

A decrease in the number of double bonds in the fatty acid tails of the membrane phospholipids makes the membrane more rigid and hence the integral protein would take more time to reach the other end of the cell

An increase in the length of the fatty acid tails of the membrane phospholipids would again increase the rigidity of the cell membrane by maximizing the hydrophobic interactions

Answer: A. Tight junctions

Explanation:

The wall of gut/intestine has a special system of barrier that, on one hand, allows the absorption of useful nutrients and on the other hand, blocks substances that should not gain access to the body. Epithelial cells that make up the wall of the intestine provide support to the barrier system. The spaces between the epithelial cells are sealed tightly by the tight junctions which consist of proteins. When a gram negative bacteria enters the body, its lipopolysaccharide endotoxin(LPS) causes the permeability of tight junctions to increase. This causes 'leaky gut'.

Plasmodesmata are a part of plants and connect adjacent plant cells

Adhesive junctions are more basal in their positioning than the tight junctions and are hence not involved

Gap junctions are cell to cell connections in adjacent animal cells and thus are like the plasmodesmata.

_____________________________

[Kindly give a thumbs up]

gladiator answered 1 year ago

Next > < Previous

Related Solutions

Sketch a membrane contain the lipid bilayer, peripheral membrane proteins, and integral membrane proteins. Label the...

Sketch a membrane contain the lipid bilayer, peripheral membrane proteins, and integral membrane proteins. Label the lipid bilayer, peripheral membrane protein, an integral membrane protein. Name the types of intermolecular forces that hold peripheral and integral membrane proteins to the membrane and name the reagents that can be used to remove each type of membrane protein from association with the membrane.

Different types of cells have different types of integral membrane proteins. What would you expect to...

Different types of cells have different types of integral membrane proteins. What would you expect to reside in the plasma membrane of an epithelial cell that might be absent from that of an erythrocyte? How do such differences relate to the activities of these cells? explain d in etail and give reference. (15points)

Which of the following factors would tend to increase membrane fluidity? A) A greater proportion of...

Which of the following factors would tend to increase membrane fluidity? A) A greater proportion of unsaturated phospholipids B) A greater proportion of saturated phospholipids C) A lower temperature D) A relatively high protein content in the membrane E) A greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses Which state correctly describes bound ribosomes? Choose all correct states. A) Bound ribosomes are enclosed in a membrane. B) Bound and free ribosomes are structurally different. C)...

3. Cell membranes contain a variety of integral and peripheral membrane proteins. a. Explain the differences...

3. Cell membranes contain a variety of integral and peripheral membrane proteins. a. Explain the differences between symport, antiport and uniport proteins compared to ion channels. b. There are a variety of glucose transport proteins in the cell membrane with some relying heavily on the sodium/potassium ATPase pump. (1) Explain this relationship and indicate how this is important to the translocation of glucose across the intestinal lumen into the blood. (2) CHALLENGE: Suggest an in vitro experiment that would allow...

1. What are the components which make up a membrane? 2. How are proteins "associated" with a membrane?

1. What are the components which make up a membrane? 2. How are proteins "associated" with a membrane? 3. What role(s) do membranes play in a cell? 4. How do molecules cross the membrane? Do all need a channel or transporter? Why? 5. What is aquaporin, what role do aquaporin play and what structure and class does it belong to? 6. How are channels different from transporters? 7. What do transporters transport? Is transport active or passive? 8. What are Na/K ATPases and how do they function...

You have mixture of proteins with the following properties. Which of these proteins would be eluted...

You have mixture of proteins with the following properties. Which of these proteins would be eluted last from an anion-exchange column when the column is developed with 1.0M NaCl in pH 7.0 buffer. Note, that the anion-exchange column was equilibrated with the pH 7.0 buffer before use. A. MW = 18,500, pI = 10.2 B. MW = 28,000, pI = 7.0 C. MW = 62,000, pI = 3.9 CORRECT ANSWER D. MW = 9,000, pI = 5.8 E. MW =...

1. Which of the following would cause an increase in the market supply of accountants (increase...

1. Which of the following would cause an increase in the market supply of accountants (increase labor supply curve) Select one: a. an increase in wages offered to tax attorneys (an occupation alternative to accounting) b. an increase the in value of the marginal product of accountants. c. a decrease in wages offered to tax attorneys (an occupation alternative to accounting) d. stricter qualifications needed to be a certified public accountant (CPA) 2. Value of the marginal product of labor...

1.) A Membrane is a boundary that __ to move across it: Allows all substances...

______ 1.) A Membrane is a boundary that ________ to move across it: Allows all substances Does not selectively control which substances Prevents all substances Selectively controls which substances ______ 2.) Membrane foundation is formed by the: Chromosomes Enzymes Phospholipids (lipid bilayer) Proteins ______ 3.) Lipid bilayer Does permit water soluble substances to pass through it into the cell: False b.) True ______ 4.) Fluid Mosaic Model describes the organization of: Cellular membranes Cellular membrane lipids only Cellular membrane proteins...

question 16. Which of the proteins below are synthesized on the membrane bound ribosome of the...

question 16. Which of the proteins below are synthesized on the membrane bound ribosome of the RER? A. Peripheral membrane proteins of plasma membrane B. The enzymes required for glycolic C. The pex5 receptor that binds preoxisomal proteins and transports them to the peroxisomal matrix D. Enzymes of the inner mitochondrial membrane E. None of the above

1. Which of the following is/are required for retrotransposons to move from one location to another...

1. Which of the following is/are required for retrotransposons to move from one location to another in the genome? Select one or MORE: a. RNA polymerase b. DNA polymerase c. ribosomes d. reverse transcriptase 2. Which of the following is/are not commonly used in gene expression and cell replication in human cells? Select one or MORE: a. ribosomes b. reverse transcriptase c. DNA-dependent RNA polymerase (DNA-->RNA) d. DNA-dependent DNA polymerase (DNA-->DNA) e. RNA-dependent RNA polymerase (RNA --> RNA) 3. Ubiquitin...

Subjects