The Ca2+ release-activated Ca2+ (CRAC) channel is the most well-documented of the store-operated ion channels that are widely expressed and are involved in many important biological processes. However, the regulation of the CRAC channel by intracellular or extracellular messengers as well as its molecular identity is largely unknown. Specifically, in the absence of extracellular divalent cations, it becomes permeable to monovalent cations with a larger conductance, however, this monovalent cation current inactivates rapidly by an unknown mechanism. Here we found that Ca2+ dissociation from a site on the extracellular side of the CRAC channel is responsible for the inactivation of its Na+ current, and Ca2+ occupancy of this site otherwise potentiates its Ca2+ as well as Na+ currents. This Ca2+-dependent potentiation is required for the normal functioning of CRAC channels.
Current is a flow of electrical charge carriers, usually electrons or electron-deficient atoms.
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Answer:
II and IV.
Explanation:
I. (INCORRECT). A model is a tentative to determinate a thing that can't be proved, and it's made based on evidence. If the model can explain the observation in nature, it is considered right, although it can be proved by a theory.
II. (CORRECT). The most accepted model of atoms says that they're formed by tiny particles, protons, neutrons, and electrons, with the first two on the nucleus, and the other surrounding it in an open space.
III. (INCORRECT). A heterogeneous mixture is a mixture of substances that is possible to identify phases of them, such as in oil and water. In the air, isn't possible to identify the constituents, and it's a homogeneous mixture.
IV. (CORRECT). Silver has atomic number 47, which is its number of protons. The atomic mass is the sum of protons and neutrons, so the number of neutrons is 108 - 47 = 61.
Answer:
The sun uses nuclear fusion reactions to generate heat.
Explanation:
It is true from the given choices that the sun uses nuclear fusion reactions to generate heat.
The heat that accompanies nuclear fusion reactions is very huge. In fact this is the source of energy for the whole solar system.
During a nuclear fusion reaction, small atomic nuclei combines to form larger ones.
This combination results in a series of chain reactions that releases energy.
Do what i don’t see nothing
Answer:
D) There are 33 particles inside of the nucleus and 16 particles outside of the nucleus.
Explanation:
Sulfur has an atomic number of 16. The atomic number represents the number of protons, so sulfur has 16 protons.
This atom of sulfur has a mass number of 33. The mass number is the sum of protons and neutrons. Then, the number of neutrons is 33 - 16 = 17
Sulfur is a neutral atom. Therefore, it has the same number of positive charges (protons) and negative charges (electrons). Thus, sulfur has 16 electrons.
Protons and neutrons are in the nucleus and electrons are outside the nucleus.
Taking all the above into account, the correct answer is:
D) There are 33 particles inside of the nucleus and 16 particles outside of the nucleus.