The directed movement of a motile cell or organism in response to light.

OBSOLETE. Specification of the borders of central gap gene expression mediated largely by the effects of other gap genes; in insects this is exemplified by knirps repression of Kruppel.

The directed movement of a cell or organism away from a source of light.

The directed movement of a motile cell or organism towards a lower level of a physical stimulus involved in energy generation, such as light, oxygen, and oxidizable substrates.

A decrease in a behavioral response to a repeated stimulus. This is exemplified by the failure of a person to show a startle response to a loud noise that has been repeatedly presented.

The chemical reactions and pathways involving ketone bodies, any one of the three substances: acetoacetate, D-3-hydroxybutyrate (beta-hydroxybutyrate) or acetone, as carried out by individual cells. Although 3-hydroxybutyrate is not a ketone, it is classed as a ketone body because it exists in an equilibrium with acetoacetate. Ketone bodies may accumulate in excessive amounts in the body in starvation, diabetes mellitus or in other defects of carbohydrate metabolism.

The chemical reactions and pathways resulting in the breakdown of ketone bodies, any one of the three substances: acetoacetate, D-3-hydroxybutyrate (beta-hydroxybutyrate) or acetone. Ketone bodies can be used as an energy source as an alternative to glucose. Utilization of ketone bodies in peripheral tissues involves conversion of acetoacetate to acetoacetyl-CoA, which is then converted to two molecules of acetyl-CoA.

The chemical reactions and pathways resulting in the formation of ketone bodies, any one of the three substances: acetoacetate, D-3-hydroxybutyrate (beta-hydroxybutyrate) or acetone. Biosynthesis involves the formation of hydroxymethylglutaryl-CoA, which is cleaved to acetate and acetyl-CoA.

The directed movement of zinc ions from inside the vacuole across the vacuolar membrane and into the cytosol.

A process in which a zinc II ion is transported from one side of a membrane to the other by means of some agent such as a transporter or pore.

OBSOLETE. The activation of genes encoding transcription factors in the posterior region of an insect embryo by a combination of maternal regulatory signals and interactions among themselves; exemplified by the activation of expression of the Drosophila knirps gene.