Answer:
Polycyclic aromatic hydrocarbons (from petroleum)
Explanation:
Polycyclic aromatic hydrocarbons (PAH) is a group of compounds which contain more than one aromatic ring. Typically examples include; naphthalene, anthracene, phenanthrene etc.
PAH are present in petroleum products. Almost everyone is regularly exposed to vehicles or other equipments that uses petroleum products as fuel. PAH is usually released from the combustion engine of these equipments and may be inhaled by humans. Thus there is a very high risk of PAH exposure compared to other items listed in the question.
PAHs are known to cause different kinds of cancer and other types of health issues in the body. The most disturbing toxicity of PAH is its carcinogenicity which makes it a very serious potential health risk for humans exposed to it on regular basis.
Answer:
Verdadero!
no se en que mas quieres que te ayude? o cual realmente quieres que sea la respuesta?
Answer:
The isoelectric point is that the <u>pH </u>at which the compound is in an electronically neutral form.
For diss equations<u>, p</u>lease find them in the enclosed file.
The pIs of 2 amino acids:
- Glutamate: pI = 3,2
- Histidine: pI = 7,6
Explanation:
Formula for the pI calculation: pI = (pKa1 + pKa2)/2
Given 3 pKa :
- Acid glutamic with an acid sidechain:
Use the lower 2 pKas (corresponding with 2 -COOH groups)
pKa1 = 2,19; pKa2 = 4,25; so pI = 3,2
- Histidine with 2 amino groups:
Use the higher 2 pKas ( -COOH group and -NH= group)
pKa1 = 6; pKa2 = 9,17; so pI = 7,6
They contain the same number of molecules; however, the masses can differ depending on the molar masses of the substances.
