Science on Tap to focus on role of simple molecules in our evolution
WEST LAFAYETTE, Ind. - A leading researcher at Purdue University will highlight how the simplest of molecules under ideal conditions may have set in motion life as we know it during the next Science on Tap talk on Feb. 16.
Barbara Golden, an associate professor of biochemistry, will speak at 6 p.m. in the upstairs of the Lafayette Brewing Company, 622 Main St., in Lafayette. The Science on Tap talk is titled, Ribozymes and the RNA World. The event is free and open to the public to those ages 21 or older.
"When we think of evolution, we tend to think about the progression of life from single, simple cells to the complex and infinite variety of organisms on Earth today," Golden said. "The first forms of 'life,' however, were likely to be simple molecules that, under the correct conditions, could replicate themselves.
"By exploring ribozymes, RNA molecules that can perform chemical reactions, we can understand how complex cells may have evolved from such simple, self-replicating molecular machines."
Sponsors for Golden's Science on Tap talk next week are the Purdue Department of Biochemistry and Discovery Park.
According to Golden, all cells are programmed by the sequence of genes encoded by DNA, a long double-helical molecule made up of four building blocks: A, G, C and T. When a gene is turned on, an RNA copy of the gene is made. RNA is closely related to DNA and is made up of four very similar building blocks: A, G, C and U.
This strand of RNA programs a cellular machine, called a ribosome, to synthesize a protein molecule from the many amino acids in the cell, she says. Each protein, such as the red hemoglobin in our bloodstream, has a unique sequence of amino acids and performs a distinct function within the cell. One type of protein, called a polymerase, even copies the DNA so that cells can divide and organisms can grow and replicate themselves, she says.
"This brings up a question about how these complex molecules could have evolved. If the sequence of the DNA encodes the sequence of a polymerase and this polymerase makes the DNA, which came first?" Golden asks. "One possibility is that RNA, or a molecule like it, was among the first self-replicating molecules on Earth. This concept is called the RNA World and it requires that RNA, like its protein counterparts, is capable of performing functions in a cell."
In recent years, she said, scientists have discovered that RNA molecules can fold into intricate and beautiful 3-D structures and that they possess a wide variety of cellular functions. Such molecules, called ribozymes, may provide a snapshot into the nature of the first self-replicating molecules on Earth.
The Science on Tap lecture series, led by Purdue graduate students Patrick Dolan, Shaili Sharma and Becca Scott, provides faculty from Purdue the opportunity to share their research activities in an informal setting, touching on subjects and providing presentations that are designed to appeal to a more general audience.
Attendance at the monthly event has averaged 80 during the program's first year.
Writer: Phillip Fiorini, 765-496-3133, pfiorini@purdue.edu
Sources: Barbara Golden, 765-496-6165, barbgolden@purdue.edu
Patrick Dolan, 765-496-9336, pdolan@purdue.edu
Related websites:
Purdue Agriculture Biochemistry Department