Consumers are living beings in a food chain that eat creatures from a particular species.
When two atoms<span> each need additional </span>electrons<span> to fill their valence shells, but neither is electro-negative enough to </span>steal electrons<span> from the other, they can form </span>another kind<span> of chemical </span>bond<span> called covalent </span>bonds<span>. In a covalent </span>bond<span>, two </span>atoms<span> move closer to share the </span>electrons<span>.</span>
Spindle fibers attach to the sister chromosomes and pull them apart. without them, the sisters would still be attached to each other which means there would be no division.
Answer:
a. Normally, PK2 activates PK1. We are told that PK1 and PK2 normally work sequentially in an intracellular signaling pathway. If PK1 is permanently activated, a response is seen independently of whether or not PK2 is present. If PK1 activated PK2, no response should be seen if PK1 were activated in the absence of PK2.
GSK-3 is an unusual protein kinase in that it displays high, “constitutive” activity in unstimulated cells and is rapidly inactivated upon a variety of cellular stimulations. The most thoroughly documented pathway for the inactivation of GSK-3 is in response to insulin and is mediated by protein kinase B (PKB, also termed Akt), which lies upstream of GSK-3 [8].