Sometimes it is difficult to tell what beginning biochemistry students struggle with more: the weight of their subject or the weight of their textbook. At six pounds and 1,100 pages, Lehninger Principles of Biochemistry is a backbreaking lesson that budding life scientists don’t soon forget.

“It’s a classic,” says Dean Molly Jahn. “It was truly the flagship text when I was a student.”

It still is—thanks largely to the efforts of biochemistry professors David Nelson and Michael Cox. The pair have edited the textbook since original author Albert Lehninger died in 1986, ushering four new editions to press, the latest of which appeared this spring. The book remains one of the most heavily used introductory texts in the field, and it has been translated into 12 languages.

But when modern students are more likely to hit Google than crack a mammoth text in search of information, even standbys like Lehninger are having to adapt to avoid extinction. Science textbooks are now accompanied by web sites and CDs full of interactive features, designed to build upon the lessons imparted through the flat reality of print. The newest Lehninger edition, for example, has an online component with rotating molecule models and “living” line graphs, which allow students to change data and observe the effect.

All of which raises the question: Do students still need the book?

“I think it’s getting harder and harder to justify,” says Monica Theis BS’79 MS’88, a lecturer in food science who co-authors Introduction to Foodservice, a 700-page primer on the food industry. “These books are expensive, and it really makes me wonder if I should be requiring them.”

Theis says she uses her textbook less in her classes than she once did. Instead, she posts readings online and brings in current examples to spark discussion. At the same time, she thinks textbooks offer an organizing device that can help students filter and apply fundamental knowledge. If she were to drop the text entirely, she says, her course “might be messy.”

Nelson agrees. “The value of writing (the textbook) is that a good book really does help students learn,” he says. “If I thought the book wasn’t having that effect, I wouldn’t touch it.”

But after hauling Lehninger around all day, some students might not want to touch it, either. And that ultimately may drive change in textbooks. “There’s a lot more we can do to make these books more accessible and less intimidating,” says Nelson. “I would imagine they’re going to look very different in the future.”