Organic Chemistry/Carboxylic acids. < Organic Chemistry. A carboxylic acid is characterized by the presence of the carboxyl group -COOH. The chemical reactivity of carboxylic acids is dominated by the very positive carbon, and the resonance stabilization that is possible should the group lose a proton.
The presence of renal tubule cells in the urine is of diagnostic significance, as it points towards an underlying kidney disease. The last type of epithelial cells are squamous cells. These cells are the largest cells seen in urine specimens. These cells are flat, usually with an angular or irregular outline.
Simple squamous epithelium consists of one layer of thin, flat epithelial cells resting on a basement membrane formed of connective tissue. It is found in such places as the alveoli of the lung and lining blood vessels. Squamous epithelial cells are flat, tightly adherent to each other, thin, and have a smooth surface.