Any help/explanation for these cell biology questions would be extremely helpful
ID: 214176 • Letter: A
Question
Any help/explanation for these cell biology questions would be extremely helpful. Thank you to anyone willing to help.
1. The resting potential of a particular nerve cell is -66 mV. Depolarization of the membrane will shift the membrane potential toward
A) -90 mV.
B) -66 mV.
C) 40 mV.
D) There will be no change.
E) There is not enough information to tell.
(I'm stuck between answer choices C and E)
2. All of the following are second messengers inside a cell except
A) calcium ions.
B) IP3
C) DAG.
D) protein kinase A
E) PDGF.
(I'm stuck between answer choices D and E)
3. IP3 binds to receptors on ________________ to release calcium ion into the cytoplasm
A) plasma membranes.
B) intracellular membranes.
C) mitochondrial membranes.
D) ER membranes.
E) lysosomes.
(I'm stuck between answer choices A and D)
4. Elongation of the microtubule occurs by the
A) addition of tubulin subunits to (–) end only .
B) addition of tubulin subunits to the (+) end only
C) addition of the tubulin subunits to the (+) end but removal from the (–) end.
D) addition of the tubulin subunits to both (+) and (–)end.
E) addition of G-actin subunits to (+) end but removal from the (–) end
(I'm stuck between answers choices B and D)
5. Axonemal microtubules
A) are highly disorganized and very unstable.
B) may be loosely associated with basal bodies.
C) are made up of G actin monomers.
D) are required to maintain axons.
E) all of the above
(I think the correct answer choice is C)
Explanation / Answer
1.
Correct: During depolarization, the membrane potential shifts rapidly from negative to positive as soon as the cell established the resting potential. In the given question depolarization of the membrane will shift membrane potential towards positive 40 mV.
Hence, the option (C) is correct.
Incorrect: The answers given in the option A and B are negative which is not possible. Hence, the options (A), (B), (D), and (E) are incorrect.
2.
Correct: protein kinase A is the target of secondary messengers but not itself is a secondary messenger. Protein kinase A is the family of enzyme and its activity depends upon the level of cyclic AMP.
Hence, the option (D) is correct.
Incorrect: calcium, IP3, DAG and PDGF are the secondary messengers. The binding of these secondary messengers to the specific regulatory molecules activate the signaling cascade in the cell.
Hence, the options (A), (B), (C) and (E) are incorrect.
3.
Correct: IP3 binds to the ER membrane. The cytosol of the ER contains Ca ions that are being released by the signaling mechanism of IP3 and DAG.
Hence, the option (D) is correct.
Incorrect: all other options are not suitable for the binding of secondary messenger IP3.
Hence, the options (A), (B), (C) and (E) are incorrect.
4.
Correct: elongation of the microtubule occurs by the addition of tubulin subunits to both the ends.
Hence, the option (D) is correct.
5.
Correct: Axonemal microtubules are highly organized and are made up of G actin monomers.
Hence, the option (C) is correct and options (A), (B), (D) and (E) are incorrect.
1.
Correct: During depolarization, the membrane potential shifts rapidly from negative to positive as soon as the cell established the resting potential. In the given question depolarization of the membrane will shift membrane potential towards positive 40 mV.
Hence, the option (C) is correct.
Incorrect: The answers given in the option A and B are negative which is not possible. Hence, the options (A), (B), (D), and (E) are incorrect.
2.
Correct: protein kinase A is the target of secondary messengers but not itself is a secondary messenger. Protein kinase A is the family of enzyme and its activity depends upon the level of cyclic AMP.
Hence, the option (D) is correct.
Incorrect: calcium, IP3, DAG and PDGF are the secondary messengers. The binding of these secondary messengers to the specific regulatory molecules activate the signaling cascade in the cell.
Hence, the options (A), (B), (C) and (E) are incorrect.
3.
Correct: IP3 binds to the ER membrane. The cytosol of the ER contains Ca ions that are being released by the signaling mechanism of IP3 and DAG.
Hence, the option (D) is correct.
Incorrect: all other options are not suitable for the binding of secondary messenger IP3.
Hence, the options (A), (B), (C) and (E) are incorrect.
4.
Correct: elongation of the microtubule occurs by the addition of tubulin subunits to both the ends.
Hence, the option (D) is correct.
5.
Correct: Axonemal microtubules are highly organized and are made up of G actin monomers.
Hence, the option (C) is correct and options (A), (B), (D) and (E) are incorrect.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.