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.

#Question id: 9282

#Unit 6. System Physiology – Plant

The rate of photosynthesis when red and far-red light are given together is greater than the sum of the rates when they are given apart, the effect provided essential

evidence in favor of the concept that photosynthesis is carried out by two photochemical systems working in tandem but with slightly different wavelength optima

this effect is known as

#Question id: 9280

#Unit 6. System Physiology – Plant

Oxygen-Evolving Organisms Have two Photosystems that Operate in Series, explain by emerson that is the Photosystem I preferentially absorbs far-red light of wavelengths greater than 680 nm; photosystem II preferentially absorbs red light of 680 nm and is driven very poorly by far-red light; Another difference between the photosystems is that,

a.) Photosystem I produces a strong reductant, capable of reducing NADP+, and a weak oxidant

b.) Photosystem I produces a very strong oxidant, capable of oxidizing water, and a weaker reductant than the one produced by photosystem II

c.) Photosystem II produces a strong reductant, capable of reducing NADP+, and a weak oxidant

d.) Photosystem II produces a very strong oxidant, capable of oxidizing water, and a weaker reductant than the one produced by photosystem I

Which statements would be CORRECT?

#Question id: 9276

#Unit 6. System Physiology – Plant

The carotenoid b-carotene, whose structure and absorption spectrum at,

#Question id: 9273

#Unit 6. System Physiology – Plant

In the higher excited state, chlorophyll is extremely unstable; it rapidly gives up some of its energy to the surroundings as heat, and enters the lowest excited state, the excited chlorophyll has four alternative pathways for disposing of its available energy: fluorescence, Heat loss, energy transfer, photochemistry; all process takes place in which wavelength,

#Question id: 9272

#Unit 6. System Physiology – Plant

#Question id: 9270

#Unit 6. System Physiology – Plant