Running their symposium like an organic chemistry class, three natural science faculty members, including a Nobel laureate, yesterday delivered lectures on microbiology and enzymology, as well as their current research interests.

William N. Lipscomb Jr., Lawrence Professor of Chemistry, discussed the structure and function of enzymes with a crowd of about 60 at the symposium "Chemistry and Physics of Biological Processes."

Displaying stereoscopic slides of one protein structure, the 1976 Nobel laureate explained that enzymes are composed of proteins, or amino acid chains, and speed up chemical reactions in living organisms.

"The enzyme does chemistry--what we call catalysis," he said.

The future of enzymatic research lies in the ability to modify an enzyme to suit certain purposes. "You can make those changes now by genetic modifications," he said.

Assistant Professor of Biochemistry Donald C. Wiley followed with a talk on the structures of viruses and his hopes to modify these organisms for therapeutic aid in humans.

"The virus can fuse itself to the cell, gain entry and thereby cause trouble," Wiley said. His aim is to modify viruses to prevent the initial fusion, he explained, demonstrating with a 5-ft. molecular model.

Swinging wires held to his chest in mimicry of a bacterium, Professor of Biology Howard C. Berg discussed mechanisms bacteria use to move at the end of the lecture.

"You just can't help but be amazed by it," he said. "I think of [the bacterium] as a ballet dancer."

Berg explained that a motor analogous to a bacterium's locomotion power would produce 6000 r.p.m., 10 horsepower, and 16 cylinders.