Death of Albrecht Kossel (German biologist, Nobel laureate in Physiology and Medicine), July 5. Albrecht Kossel was a prominent German scientist in the fields of biology and chemistry who died on this date in 1927. He is recognized for his foundational research on the structure and composition of nucleic acids and proteins. In 1910, Kossel was awarded the Nobel Prize in Physiology and Medicine for his discovery of the principal components of cell nuclei. Born in 1853 in Rostock, Germany, Kossel spent much of his academic career at German universities. He succeeded in identifying five key constituents of the cell nucleus, which played a significant role in advancing molecular biology. His research laid the groundwork for a better understanding of genetic structure and cellular function, paving the way for later discoveries in genetics and cell biology. Kossel's death on July 5, 1927, marked a turning point in the history of biology. His scientific works continue to be influential in biological and medical education and research, and his name is recorded as one of the pioneers of molecular biology. This date serves as a reminder of his important role in the advancement of human knowledge. This observance was added to the Gregorian calendar after his death in 1927 to honor his significant scientific contributions and lasting impact on biology.