Evidence Question #71. Various types of vesicle coats have been implicated in membrane traffic pathways suchas endocytosis, export from the ER to the Golgi, and transport between Golgicisternae. But so far, no coat has been identified for the secretory vesicles that carrymaterial from the Golgi to the plasma membrane. Do you think such a coat is likely toexist? Justify your answer.2. A muscle cell contains acetylcholine receptors that act as ligand-gated cation channels,and it also contains voltage-gated Na+ channels of the type found in neurons. Intheory, could a muscle cell get away with having only acetylcholine-gated cationchannels, which would serve the dual purpose of receiving neurotransmitter signalsand propagating action potentials? Why or why not?3. Fluorescent FM dyes partition reversibly into biological membranes withoutpenetrating through them. Suppose that you have neurons cultured in a dish. Youincubate the neurons with an FM dye, and then you wash them with medium toremove the dye.a) You find that if the neurons are stimulated to trigger action potentials duringincubation with the dye, the synaptic regions of the neurons remain fluorescentafter the wash. Propose an explanation for this effect.b) After generating fluorescent synaptic regions by this procedure, suppose that youtrigger additional action potentials while continuing to wash with medium. Wouldyou expect the synaptic regions to lose fluorescence? Explain.

The study of vesicle trafficking in cells is a fascinating area of research in cell biology, as it…

1. Various types of vesicle coats have been implicated in membrane traffic pathways such as endocytosis, export from the ER to the Golgi, and transport between Golgi cisternae. But so far, no coat has been identified for the secretory vesicles that carry material from the Golgi to the plasma membrane. Do you think such a coat is likely to exist? Justify your answer.

1. Various types of vesicle coats have been implicated in membrane traffic pathways such as endocytosis, export from the ER to the Golgi, and transport between Golgi cisternae. But so far, no coat has been identified for the secretory vesicles that carry material from the Golgi to the plasma membrane. Do you think such a coat is likely to exist? Justify your answer.

Biology 2e

2nd Edition

ISBN:9781947172517

Author:Matthew Douglas, Jung Choi, Mary Ann Clark

Publisher:Matthew Douglas, Jung Choi, Mary Ann Clark

Chapter4: Cell Structure

Section: Chapter Questions

Problem 20RQ: Which of the following do not play a role in intracellular movement? microfilaments and intermediate...

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Which statements are true? Explain why or why not.1 The role of ATP hydrolysis in actin polymerizationis similar to the role of GTP hydrolysis in tubulin polym-erization: both serve to weaken the bonds in the polymerand thereby promote depolymerization.2 Motor neurons trigger action potentials in musclecell membranes that open voltage-sensitive Ca2+ channelsin T tubules, allowing extracellular Ca2+ to enter the cyto-sol, bind to troponin C, and initiate rapid muscle contrac-tion.3 In most animal cells, minus-end directed microtu-bule motors deliver their cargo to the periphery of the cell,whereas plus-end directed microtubule motors delivertheir cargo to the interior of the cell.
Question 9. When the rate of loss of actin subunits from the pointed end of an actin filament is balanced by the rate of their addition to the barbed end what is this state called?
Give 4 similarities and 4 differences between and nature and/or role of membrane potentials in a neuron and in a mitochondrion.
Muscle cells require a lot of energy to operate normally. Thus, muscle cells likely contain a high number of: [Select the best answer. ] mitochondria lysosomes vacuoles nuclei transport vesicles smooth endoplasmic reticulum rough endoplasmic reticulum golgi complexes ribosomes
QUESTION 2: Select the correct statement regarding the actin cytoskeleton O They are involved in the formation of the axoneme Actin microfilaments are the most stable rytoskeleton network can undergo catastrophe due to GTP hydrolysis-mediated conformational changes Synthesis and degradation of actin microfiaments is directional with g-actin subunits added only to the end of the microflament while depolymerization occurs at the end. QUESTION 3: From the list below salect the correct statements regarding the genetic code The basis of the genetic code are codons Cosons are formed by 5 consecutive nucleotides The genetic code has a possibile 64 different codem Codos code for 30 distinct amo acas The genetic code has built in degeneracy
HEL 9. Consider the membrane protems in question 7. What cellular functions must always be performed by an integral membrane protein? Explain. NEL 2.2 Membrane Structure and Functio
Question 7. What is the rate-limiting step in the formation of an actin microfilament?
cell defense worksheet (1) [Compatibility Mode] Qv Search in Docume Insert Draw Design Layout References Mailings Review View Acrobat A. Century Gothic - 12 A A- U - abe X,2 x² A A Styles Styles Pane Create and Adobe PI Step 13: Take the "Energy and Transport Challenge!" How many ATP did you use? What type(s) of protein(s) were used? Explain when each type was used. Step 14: Take the "Osmosis Challenge!" What is Osmosis? What is the name of the special proieins that let water pass through? Is this passive or active transport? Step 15: From your Scores Sheet record: Lab Score (% correct): Number Correct: Numbar Incen et Page 2 of 3 * English (United States) 505 words E Focus MAR 15 MacBook Air 888 F1 F2 F3 F4 F5 F6 F7 F @ %23 $ & 7 8. Q W T Y
molecules of actin could it hold? Assume the cell is spherical The Size of Cells and Their Components (a) If you were to magnify a cell 10,000-fold (typica] of u magnification achieved using an electron microscope), ho ples of Bioch 1. yotic cell with a cellular diameter of 50 µm. (b) If this cell were a muscle cell (myocyte), how many and no other cellular components are present; actin molecules are spherical, with a diameter of 3.6 nm. (The volume of a sphere is %ar.) (c) If this were a liver cell (hepatocyte) of the same dimensions, how many mitochondria could it hold? Assume the cell is spherical; no other cellular components are pre- sent; and the mitochondria are spherical, with a diameter of 1.5 µm. h (d) Glucose is the major energy-yielding nutrient for most cells. Assuming a cellular concentration of 1 mM (that is, 1 millimole/L), calculate how many molecules of glucose would be present in our hypothetical (and spherical) eukaryotic cell. (Avogadro's number, the number of…
QUESTION 13 What is the mechanism by which microtubules can rapidly shrink, or undergo â catastrophe?â A At low levels of ATP, tubulin subunits are not added to the + end of the microtubule. B At low levels of GTP, beta-tubulin subunits at the + end of the microtubule hydrolyze GTP, undergo a conformational change, and destabilize the filament so that the filament starts to disassemble from the + end. C At low levels of GTP, tau proteins are phosphorylated and bind to the microtubule to destabilize the + end. D At high levels of GTP, tubulin subunits are more quickly added to the â end than to the + end of the microtubule, resulting in a shrinking + end of the microtubule. E At low levels of ATP, the microtubules rapidly disassemble since ADP-bound tubulin subunits are lost at both the + and â ends of the filament.
Which statements are true? Explain why or why not.1 Given the numerous processes inside cells thatare regulated by changes in Ca2+ concentration, it seemslikely that Ca2+-dependent cell–cell adhesions are alsoregulated by changes in Ca2+ concentration.2 Tight junctions perform two distinct functions:they seal the space between cells to restrict paracellularflow and they fence off plasma membrane domains toprevent the mixing of apical and basolateral membraneproteins.3 The elasticity of elastin derives from its high con-tent of α helices, which act as molecular springs.4 Integrins can convert mechanical signals intointracellular molecular signals.
One of three mechanisms of ER membrane remodeling is motor-independent membrane sliding along microtubule shafts. true or false