Question 1

Which of the following has not been identified as a phosphoinositide? A)PI(3)P B)PI(4)P C)PI(5)P D)PI(6)P E)PI(3,4)P₂

Accepted Answer

PI(6)P has not been identified as a phosphoinositide. All the other options given (PI(3)P, PI(4)P, PI(5)P, and PI(3,4)P₂) have been identified as phosphoinositides.

Question 2

The phosphorylated rings of phosphoinositides are recognized and bound by particular proteins.Where are the phosphorylated rings located?
A)They reside in the membrane interior.
B)They are found in lysosomes.
C)They reside at the membrane surface.
D)They reside inside the clathrin coat.
E)They reside inside the COPII-coat.

Accepted Answer

The phosphorylated rings of phosphoinositides are located at the membrane surface, where they can be recognized and bound by specific proteins.

Question 3

The inner leaflet of the plasma membrane contains elevated levels of PI(4,5)P₂,which plays an important role in the recruitment of proteins involved in clathrin-mediated endocytosis,like ______ and ______? A)AP3,dynamin B)AP2,dynamin. C)TGN,dynamin D)TGN,dynamin. E)clathrin,dynamin

Accepted Answer

The elevated levels of PI(4,5)P₂ in the inner leaflet of the plasma membrane recruits proteins involved in clathrin-mediated endocytosis, including AP2 and dynamin.

Question 4

Which of the following is a difference between the coats of COPII- and clathrin-coated vesicles?
A)The inner layer of adaptor proteins of COPII-coated vesicles overlap extensively,while those of clathrin-coated vesicles do not overlap.
B)The outer scaffold subunits of the clathrin lattice of coated vesicles overlap extensively,while those of the COPII lattice of coated vesicles do not overlap.
C)The outer scaffold subunits of the COPII lattice of coated vesicles overlap extensively,while those of the clathrin lattice of coated vesicles do not overlap.
D)The clathrin-coated vesicles have three distinct layers,while the COPII-coated vesicles have two distinct layers.

Accepted Answer

The outer scaffold subunits of the clathrin lattice of coated vesicles overlap extensively, while those of the COPII lattice of coated vesicles do not overlap. This is because clathrin-coated vesicles form a cage-like structure, made up of three heavy chains and three light chains that self-assemble into a lattice, while COPII-coated vesicles have a simpler structure with two layers.

Question 5

Which molecule below is a GTP-binding protein that is required for the release of a clathrin-coated vesicle from the membrane on which it was formed?
A)AP2
B)GGA
C)clathrin
D)dynamin
E)opsonin

Accepted Answer

Dynamin is a GTP-binding protein that is required for the release of a clathrin-coated vesicle from the membrane on which it was formed. AP2 and GGA are adaptor proteins that help clathrin bind to the membrane and cargo molecules. Clathrin is a structural protein that forms a lattice on the vesicle membrane. Opsonin is a molecule that marks pathogens for phagocytosis.

Question 6

The best-studied adaptors that participate in the formation of the coated pits and coated vesicles of clathrin-mediated endocytosis are the _____ adaptors.
A)COPII
B)GGA
C)AP2
D)clathrin
E)COPI

Accepted Answer

AP2 is the best-studied adaptors that participate in the formation of coated pits and coated vesicles of clathrin-mediated endocytosis. COPII adapts to the formation of vesicles that transport proteins from the endoplasmic reticulum to the Golgi apparatus while GGA and COPI adapt to the formation of vesicles that transport cargo within the Golgi and from the trans-Golgi network to endosomes or lysosomes, respectively. Clathrin is a structural protein that forms the outer shell of the coated pit or vesicle.

Question 7

The phosphorylated rings of phosphoinositides are recognized and bound by particular proteins.Where are the phosphorylated rings located?
A)They reside in the membrane interior.
B)They are found in lysosomes.
C)They reside at the membrane surface.
D)They reside inside the clathrin coat.
E)They reside inside the COPII-coat.

Accepted Answer

The phosphorylated rings of phosphoinositides are located at the membrane surface, where they can be recognized and bound by specific proteins.

Question 8

The three-legged assembly of protein chains that makes up a clathrin molecule and that can assemble into a network of polygons resembling a honeycomb is called a(n)_____.
A)trigeminy
B)triskeleton
C)trigellium
D)triskelion
E)triskellium

Accepted Answer

The term for the three-legged assembly of protein chains that makes up a clathrin molecule is "triskelion". The other choices (trigeminy, triskeleton, trigellium, triskellium) are not correct scientific terms for this structure.

Question 9

What molecules do the AP2 adaptors of the clathrin coat connect?
A)GGA adaptors and clathrin molecules
B)the cytoplasmic tails of specific membrane receptors and clathrin molecules
C)the luminal tails of specific membrane receptors and clathrin molecules
D)the clathrin molecules and cargo molecules
E)cargo molecules and the cytoplasmic tails of specific membrane receptors

Accepted Answer

The answer of What molecules do the AP2 adaptors of...

Question 10

How do early endosomes mature into late endosomes? How is this population of vesicles formed? What name is often given to late endosomes because of the population of vesicles located inside the endosome?

Accepted Answer

The answer of How do early endosomes mature into late...

Question 11

The uptake of relatively large particulate matter into the cell is called _________.
A)endocytosis
B)phagocytosis
C)autophagy
D)exocytosis
E)pinocytosis

Accepted Answer

Phagocytosis is the process by which relatively large particulate matter or whole cells are engulfed by a cell. Endocytosis is a general term for any process by which a cell takes in molecules or particles from the outside by engulfing them in a vesicle. Autophagy is the process of self-eating by a cell, where a cell breaks down its own components. Exocytosis is the reverse process of endocytosis, and pinocytosis is a type of endocytosis where a cell takes in small droplets of fluid or solutes. Therefore, none of the other choices specifically refer to the uptake of large particulate matter.

Question 12

Which of the following strategies is used by Mycobacterium tuberculosis,the bacterium responsible for tuberculosis,to avoid being destroyed by phagocytosis?
A)The bacterium crystallizes the enzymes in the phagolysosome.
B)The bacterium inhibits fusion of the phagosome with a lysosome.
C)The bacterium allows fusion with the lysosome,but neither the acidic pH nor the lysosomal enzymes can destroy it.
D)The bacterium produces proteins that destroy lysosomal membrane integrity so that the bacterium can escape into the cell cytosol.
E)The bacterium neutralizes the enzymes in the lysosome.

Accepted Answer

Mycobacterium tuberculosis avoids being destroyed by phagocytosis by inhibiting fusion of the phagosome with a lysosome. This allows the bacterium to reside in the phagosome and eventually replicate within it.

Question 13

What types of molecules below can a cell internalize by receptor-mediated endocytosis?
A)hormones and growth factors
B)enzymes
C)bloode-borne proteins carrying certain nutrients
D)hormones and growth factors and enzymes
E)All of these are correct

Accepted Answer

All of these molecules can be internalized by receptor-mediated endocytosis, as this mechanism specifically allows cells to target and take up specific molecules that are needed for various cellular processes. Hormones and growth factors can help regulate various processes in the body, while enzymes are important for catalyzing specific chemical reactions. Blood-borne proteins carrying certain nutrients, such as transferrin or low-density lipoprotein (LDL), can be taken up by cells through specific receptor-mediated mechanisms.

Question 14

Substances that enter the cell by receptor-mediated endocytosis bind receptors that collect in specialized domains of the plasma membrane called ______.
A)coated vesicles
B)coated pits
C)RME pits
D)gap junctions
E)tight junctions

Accepted Answer

Substances that enter the cell by receptor-mediated endocytosis bind to receptors that are collected in specialized regions of the plasma membrane called coated pits. Coated pits are regions where the plasma membrane is invaginated and coated with proteins such as clathrin, which help to form coated vesicles for intracellular transport.

Question 15

The vesicle containing material taken into the cell by phagocytosis is called a(n)_________.
A)phagocytosome
B)vacuolosome
C)phagosome
D)phagolysosome
E)exosome

Accepted Answer

The term for the vesicle formed when a cell engulfs material through phagocytosis is called a phagosome. It merges with lysosomes to form a phagolysosome where the material is broken down.

Question 16

What drives the engulfment of particulate material by phagocytosis?
A)contractile activities of the actin-containing microfilaments that underlie the plasma membrane
B)contractile activities of the tubulin-containing microtubules that underlie the plasma membrane
C)contractile activities of the actin-containing microfilaments that underlie the mitochondrial membrane
D)contractile activities of the myosin-containing microfilaments that underlie the plasma membrane
E)contractile activities of the tubulin-containing microtubules that underlie the mitochondrial membrane

Accepted Answer

The engulfment of particulate material by phagocytosis is driven by the contractile activities of the actin-containing microfilaments that underlie the plasma membrane. These microfilaments form a structure called the phagocytic cup, which surrounds the particulate material being engulfed and eventually seals off to form a phagosome. Myosin and tubulin-containing microtubules are not involved in phagocytosis. The mitochondria are not directly involved in phagocytosis, although they do play a role in cellular energy production.

Question 17

What helps to give different membrane compartments their own unique surface identity?
A)the different proteins contained within them
B)the different surface nucleotides in each one
C)the different shapes of the different membrane compartments
D)the degree of concentration of the contents of the membrane compartments

Accepted Answer

The different proteins contained within each membrane compartment can contribute to its unique surface identity by serving as markers, receptors, or channels. These proteins can interact with other molecules within the cell or in the extracellular environment, and can help to distinguish one compartment from another. While the other factors listed may also contribute to membrane identity in some cases, the presence of specific proteins is likely the most important determinant.

Question 18

The inner leaflet of the plasma membrane contains elevated levels of _____,which plays an important role in the recruitment of proteins involved in clathrin-mediated endocytosis,like dynamin and AP2. A)PI(4,5)P₂ B)PI(4)P C)PI(3,5)P₂ D)PI(3,4)P₂ E)PI(5)P

Accepted Answer

PI(4,5)P2 (Phosphatidylinositol 4,5-bisphosphate) is known for its role in clathrin-mediated endocytosis, where it recruits proteins such as dynamin and AP2 to the plasma membrane.

Question 19

If you treated a macrophage with colchicine (a microtubular inhibitor),what would be likely to happen to the rate of phagocytosis? What would be likely to happen to the rate of phagocytosis if you treated the macrophage with an inhibitor of microfilament contractile activities?
A)Nothing would happen after colchicine exposure.The rate would rise after cytochalasin B exposure
B)The rate would drop after colchicine exposure.Nothing would happen after cytochalasin B exposure.
C)Nothing would happen after colchicine exposure.The rate would drop after cytochalasin B exposure.
D)The rate would rise after colchicine exposure.Nothing would happen after cytochalasin B exposure.
E)Nothing would happen after treatment with either inhibitor.

Accepted Answer

The answer of If you treated a macrophage with colchicine...

Question 20

Which of the following strategies is used by Listeria monocytogenes,a bacterium that causes meningitis,to avoid being destroyed by a lysosome's fusion with the phagosome in which it was ingested?
A)The bacterium allows fusion with the lysosome,but the acidic pH cannot destroy it.
B)The bacterium inhibits fusion of the phagosome with a lysosome.
C)The bacterium allows fusion with the lysosome,but the lysosomal enzymes cannot destroy it.
D)The bacterium produces proteins that destroy lysosomal membrane integrity so that the bacterium can escape into the cell cytosol.
E)The bacterium neutralizes the enzymes in the lysosome.

Accepted Answer

The answer of Which of the following strategies is used...

Quiz 8: Cytoplasmic Membrane Systems: Structure, Function, and Membrane Trafficking

Which of the following has not been identified as a phosphoinositide?

The phosphorylated rings of phosphoinositides are recognized and bound by particular proteins.Where are the phosphorylated rings located?

The inner leaflet of the plasma membrane contains elevated levels of PI(4,5) P₂,which plays an important role in the recruitment of proteins involved in clathrin-mediated endocytosis,like and ?

Which of the following is a difference between the coats of COPII- and clathrin-coated vesicles?

Which molecule below is a GTP-binding protein that is required for the release of a clathrin-coated vesicle from the membrane on which it was formed?

The best-studied adaptors that participate in the formation of the coated pits and coated vesicles of clathrin-mediated endocytosis are the _____ adaptors.

The phosphorylated rings of phosphoinositides are recognized and bound by particular proteins.Where are the phosphorylated rings located?

The three-legged assembly of protein chains that makes up a clathrin molecule and that can assemble into a network of polygons resembling a honeycomb is called a(n) _____.

What molecules do the AP2 adaptors of the clathrin coat connect?

How do early endosomes mature into late endosomes? How is this population of vesicles formed? What name is often given to late endosomes because of the population of vesicles located inside the endosome?

The uptake of relatively large particulate matter into the cell is called _________.

Which of the following strategies is used by Mycobacterium tuberculosis,the bacterium responsible for tuberculosis,to avoid being destroyed by phagocytosis?

What types of molecules below can a cell internalize by receptor-mediated endocytosis?

Substances that enter the cell by receptor-mediated endocytosis bind receptors that collect in specialized domains of the plasma membrane called ______.

The vesicle containing material taken into the cell by phagocytosis is called a(n) _________.

What drives the engulfment of particulate material by phagocytosis?

What helps to give different membrane compartments their own unique surface identity?

The inner leaflet of the plasma membrane contains elevated levels of _____,which plays an important role in the recruitment of proteins involved in clathrin-mediated endocytosis,like dynamin and AP2.

If you treated a macrophage with colchicine (a microtubular inhibitor) ,what would be likely to happen to the rate of phagocytosis? What would be likely to happen to the rate of phagocytosis if you treated the macrophage with an inhibitor of microfilament contractile activities?

Which of the following strategies is used by Listeria monocytogenes,a bacterium that causes meningitis,to avoid being destroyed by a lysosome's fusion with the phagosome in which it was ingested?

Quiz 8: Cytoplasmic Membrane Systems: Structure, Function, and Membrane Trafficking

Which of the following has not been identified as a phosphoinositide?

The phosphorylated rings of phosphoinositides are recognized and bound by particular proteins.Where are the phosphorylated rings located?

The inner leaflet of the plasma membrane contains elevated levels of PI(4,5) P2,which plays an important role in the recruitment of proteins involved in clathrin-mediated endocytosis,like ______ and ______?

Which of the following is a difference between the coats of COPII- and clathrin-coated vesicles?

Which molecule below is a GTP-binding protein that is required for the release of a clathrin-coated vesicle from the membrane on which it was formed?

The best-studied adaptors that participate in the formation of the coated pits and coated vesicles of clathrin-mediated endocytosis are the _____ adaptors.

The phosphorylated rings of phosphoinositides are recognized and bound by particular proteins.Where are the phosphorylated rings located?

The three-legged assembly of protein chains that makes up a clathrin molecule and that can assemble into a network of polygons resembling a honeycomb is called a(n) _____.

What molecules do the AP2 adaptors of the clathrin coat connect?

How do early endosomes mature into late endosomes? How is this population of vesicles formed? What name is often given to late endosomes because of the population of vesicles located inside the endosome?

The uptake of relatively large particulate matter into the cell is called _________.

Which of the following strategies is used by Mycobacterium tuberculosis,the bacterium responsible for tuberculosis,to avoid being destroyed by phagocytosis?

What types of molecules below can a cell internalize by receptor-mediated endocytosis?

Substances that enter the cell by receptor-mediated endocytosis bind receptors that collect in specialized domains of the plasma membrane called ______.

The vesicle containing material taken into the cell by phagocytosis is called a(n) _________.

What drives the engulfment of particulate material by phagocytosis?

What helps to give different membrane compartments their own unique surface identity?

The inner leaflet of the plasma membrane contains elevated levels of _____,which plays an important role in the recruitment of proteins involved in clathrin-mediated endocytosis,like dynamin and AP2.

If you treated a macrophage with colchicine (a microtubular inhibitor) ,what would be likely to happen to the rate of phagocytosis? What would be likely to happen to the rate of phagocytosis if you treated the macrophage with an inhibitor of microfilament contractile activities?

Which of the following strategies is used by Listeria monocytogenes,a bacterium that causes meningitis,to avoid being destroyed by a lysosome's fusion with the phagosome in which it was ingested?

The inner leaflet of the plasma membrane contains elevated levels of PI(4,5) P₂,which plays an important role in the recruitment of proteins involved in clathrin-mediated endocytosis,like and ?