Star Turn

Using computer simulations of molecular structures has enabled students at Essex University to visualise chemical processes and has improved their grades. Jennifer Currie reports.

Teaching life science students to think small is no easy task, according to Chris Reynolds, a lecturer in Essex University's biological sciences department.

"Even top scientists find it difficult to visualise what is happening at an atomic and molecular level. So we introduced computer sessions to help them learn by applying the techniques themselves. Such skills are extremely important in drug discovery and the PC sessions are an attempt to improve their understanding," Reynolds says.

Flickering on the screens in this particular computer cluster are brightly coloured, three-dimensional molecular structures that can be rotated and enlarged with a single click of the mouse.

Robert Hudson, 21, a final-year biochemistry and molecular science student, is scrutinising the bonding between his molecule and its receptor.

"This approach is a lot better than learning in traditional lectures," he says. "You get to see how the molecules actually interact." He deftly swivels the image around to view it from another perspective and pronounces the match good.

Intended as a supplement to the theory-based drug discovery lectures, the computer sessions have gone down well and exam marks have improved.

"It makes a pleasant change from scribbling a terrific amount down in a lecture theatre," says Duncan Potts, 23, also a final-year BMS student. "I have just had an interview for a PhD and the interview panel definitely saw it as an advantage that I had used these computer programmes."

Although the software is routinely used in research, only a few biology departments in Britain specialise in drug design, so the students at Essex are well placed under the direction of Reynolds, who also seems to prefer this style of teaching.

"I enjoy wandering around and talking to the students like this. But although using the computers to build protein structures is useful, they have to understand that there is a difference between the model and the real thing."

Reynolds uses a toy car to illustrate this point. "This is not a car itself, but is only a model representing what a car looks like. The difference is important."

To hammer the point home, students have to embark on a bit of homology modelling, which, translated into simpler terms, means to plonk one blob on top of another blob to see how well they match. The students are given the target amino acid sequence of a protein with unknown structure and function. After searching the database for similar sequences, the students have to align them and then mutate the amino acids in the known structure until they match those of the target sequence.

"This will be an important way of gaining information from the human genome project," Reynolds adds.

This activity proves to be a bit more tricky than the other exercises, but Nikolaos Karachalias, 22, another third-year BMS student, is quite impressed with his match. "By altering the structure just slightly we can make the drugs work in a better way," he says. "Looking at the molecules in such close detail is something we can't do in the lab and although using the programme did take a bit of getting used to, it is really fascinating. It also means we have a better idea of what is going on when we actually get to the lab to make the drugs."

In another corner of the lab, Estelle Bryant, 21, who plans to enter teaching next year, is using statistics to link the physical properties of the drug she is examining to types of activity. To the uninitiated, the screen she scrolls down, reads as nothing but gobbledegook.

"These calculations would be impossible without a computer," she sighs. "The computer programme can tell us if the structural improvements are going to work or not and save us a lot of time. Using them is definitely a huge advantage."