1.4 Chemical Determination. Proteins are complex, organic compounds composed of many amino acids linked together through peptide bonds and cross-linked between chains by sulfhydryl bonds, hydrogen bonds and van der Waals forces.
What causes pleurisy? In young, healthy people, an infection of the lower respiratory system by a virus or bacteria may cause pleurisy. Pleurisy usually lasts a few days to 2 weeks. In very rare cases, the virus or bacteria may spread and cause pleurisy in others. Other causes of pleurisy include air leaking into the pleural cavity from a hole in a lung (pneumothorax), injury to the chest (such as a broken rib), tuberculosis or other infections, or a tumor in the pleura.
Some of the causes of pleurisy include: 1  Lung infections, like tuberculosis and pneumonia. 2  Injuries to the chest. 3  Other medical conditions, such as systemic lupus erythematosus (SLE), cancer, rheumatoid arthritis, pulmonary embolism and liver diseases. 4  Reactions to certain medicines.