In heart muscle, activation series of the muscarinic acetylcholine receptor its effector K+ channel via the Gβγ subunit of a Gi protein.

a. Binding of acetylcholine triggers activation of the Gαi subunit and its dissociation from the Gβγ subunit in the usual way. 

b. The released Gβγ subunit (rather than Gαi∙GTP) binds to and opens the associated effector protein, a K+ channel. 

b. The increase in K+ permeability hyperpolarizes the membrane, which reduces the frequency of heart muscle contraction. 

d. Activation is terminated when the GTP bound to Gαi is hydrolyzed (by a GAP enzyme that is an intrinsic part of the Gαi subunit) to GDP and Gαi∙GDP recombines with Gβγ.

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#Question id: 12025

#Unit 7. System Physiology – Animal

After surgical removal of an infected gallbladder, a person must be especially careful to restrict dietary intake of ________.

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#Question id: 17082

#Unit 12. Applied Biology

What is an Aminopterin

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#Question id: 26923

#Unit 10. Ecological Principles

Resource partitioning allows____

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#Question id: 17658

#Unit 7. System Physiology – Animal

Which of the following is the most accurate description of stress?

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#Question id: 5363

#Unit 8. Inheritance Biology

A Southern blot using a probe that binds to the region spanning the mutation causing albinism detects one DNA fragment in homozygous normal individuals (A/A) and two fragments in albino individuals (a/a). Following banding pattern of three offspring of parents? Which of the following correct regarding parents?