Answer:
1) Ubiquitin is a relatively small protein that is widely expressed in eukaryotic cells.
2) It is covalently attached to target proteins in an ATP-dependent reaction.
4) Target selection is determined by ubiquitin-protein ligases.
Explanation:
Ubiquitin is a eukaryotic protein. It is very small in size and is highly conserved among the various species of eukaryotes. The function of ubiquitin is to mark an intracellular protein for degradation by proteasomes. Attachment of first ubiquitin to the target protein facilitates the joining of more ubiquitin molecules. The tagged protein enters proteolytic degradation. The ubiquitin molecules are covalently attached to a Lys residue in the target protein.
Ubiquitin specifically becomes covalently attached to the lysine residues of the target protein. This reaction is mediated by the ubiquitinating enzyme in an ATP dependent manner. Specific recognizing proteins recognize the target protein and facilitate the ligation of ubiquitin to target it for destruction by proteasomes.
If the earth wasn't spinning , we wouldn't have summer, winter, fall, spring etc, it is important because we need the sun for certain seasons and no sun for others.
Perhaps the habitat has changed, for example, dried up, so not much green vegetation. The green beetles are thus more vulnerable, favouring the brown ones. With less green beetles to take part in mating, relatively more g alleles are present, to the point that they become the majority.
<span>The decomposers maintain the natural balance of matter during the cycle in which inorganic matter is transformed into organic by the photosynthesis that will pass from one consumer to another in the food chains. When these and the producers die or eliminate of their body the products of waste these substances return to the soil the mineral matter.</span>
