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.
Answer:
The brick
The brick has the greater mass, therefore has the greater density. The
particles in a brick are more tightly packed together. Density is an
indication of how tightly packed the particles in the substance are
Hydrophobic and hydrophilic bond/interactions are common bond that forms long chains of proteins.
Some complex forms of proteins are made of subunits in which molecules bond together to form a larger unit. A good example is the blood protein hemoglobin. Hemoglobin consists of protein subunits known as the globin molecules. These subunits are folded chains of a large number of different amino acids which are known as polypeptides.
