Answer:
Low phenylalanine concentration:
- If the enzyme is inactive, PAH will look like its inactive form, with phenylalanine located in the allosteric site / inactive site so that PAH is a different shape. This will not allow as much phenylalanine to be converted into tyrosine, as we wait for Phe levels to increase.
High phenylalanine concentration:
- If the enzyme is active, PAH will look like its regular form, with an open active site that's the size of phenylalanine so that reactions can occur. (Like a hand fitting into a glove, or a lock into a key.) Phenylalanine will be the substrate, the thing acted upon by the enzyme. This will eventually raise the amount of tyrosine that's created and lower the concentration of phenylalanine.
Think about it like this. Ever heard of homeostasis? That's how the body likes to be the same, keep everything regulated, all the time. So if there are high levels of something, the body is going to try to keep that something down, and if there are low levels, it's going to try to increase the concentration of that thing.
B. the oceans is the largest ecosystem.
Answer:
Erect.
Explanation:
Paranasal sinuses are the group of air filled sacs that are present around the nasal cavity. Paranasal sinuses are present four in numbers. These are maxillary sinuses, frontal sinuses, ethmoidal sinuses and sphenoidal sinuses.
The radiography of paranasal sinuses using X ray technique is helful in medical diagnosing. The erect position provides the best image for the radiography of paranasal sinuses.
Thus, the correct answer is option (A).
The glandular swelling is found on the back of the earthworm and is called C.litellum.
An earthworm is tube shaped and it belongs to the Annelida phylum. It is usually found in the soil, where it contribute to the level of fertility of the soil by feeding on the dead organic matter and by aerating the soil. Earthworms lack internal skeletons and they are hermaphrodites.
