Minor species. For an amino acid such as alanine, the major species in solution at pH 7 is the zwitterionic form. Assume a pKa value of 8 for the amino group and a pKa value of 3 for the carboxylic acid. Estimate the ratio of the concentration of the neutral amino acid spe- cies (with the carboxylic acid protonated and the amino group neutral) to that of the zwitterionic species at pH 7 (Section 1.3).

Explanation:

Using the Henderson-Hasselbach equation, we find the ratio of alanine-COOH to alanine-COO- at pH 7 to be 10power-4. The ratio of alanine-NH2 to alanine-NH3+, determined in the same fashion, is 10power -1. Thus, the ratio of neutral alanine to zwitterionic species is 10-4 × 10 power-1 = 10power-5.

coal is not sustainable because it will one day run out.

prophase: we can observe the chromosomes to coil up and condense. they become visible. nuclear membrane and envelope disintigrate.s

metaphase: chromosomes align at the center, the metaphase plate. spindle fibers attach to centromeres of the sister chromatids. they meet at kinetochores.

anaphase: sister chromatids are pulled towards each opposing centromere, set on different poles.

telophase: chromosomes are now clustered up only on either sides of the cell. nuclear membranes reform, and a new cell wall forms along the cell plate. this will lead to cytokinesis, the process that divides the cell membrane and forms the cell wall.