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: 10501

#Unit 6. System Physiology – Plant

Which defenses require specific detection systems and signal transduction pathways that can sense the presence of an herbivore or pathogen and alter gene expression and metabolism accordingly

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#Question id: 426

#Unit 1. Molecules and their Interaction Relevant to Biology

Which statement is not true about catabolic pathways?

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#Question id: 24642

#Unit 10. Ecological Principles

 Which of the following is not the component of Soil?

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#Question id: 4609

#Unit 11. Evolution and Behavior

Pseudogenes are ________.

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#Question id: 9263

#Unit 9. Diversity of Life Forms

These data would support which of the following conclusions?