In Indiana University’s classrooms, Karlijn Keijzer was known as an intellectual doctoral chemistry student from the Netherlands, who spent long days testing anti-cancer and Alzheimer’s drugs. In campus sports, she was a feisty and formidable athlete who spent long mornings on the rowing team.

But she will always be remembered by her friends for one long festive night when she showed up to a costume party dressed as a giant piece of corn.

The 25-year-old student — who was back in the Netherlands just for the summer and planned to return to Bloomington in the fall — was killed along with the 297 other passengers when their Malaysia Airlines flight from Amsterdam to Kuala Lumpur was shot down over Ukraine.

Keijzer’s boyfriend was also on the plane: Laurens van der Graaff. He was a 29-year-old teacher. Friends said they’d been dating just a year and were madly in love. Photographs online and on Facebook show a young, good-looking couple laughing together, arms around one another, blue eyes glowing.

President Obama said Friday that at least one U.S. citizen was killed in the crash: Quinn Lucas Schansman. The victims included 189 Dutch citizens, 44 from Malaysia and 27 from Australia. Other nationalities were represented in smaller numbers: 12 Indonesians, nine from Britain, four from Germany, one from Canada.

Karlijn Keijzer is shown in this portrait from Indiana University. (Mike Dickbernd/Indiana University)

Keijzer, who was a straight A student and IU teaching assistant, loved the Midwest, said Alex Burkle, a former teammate who described Keijzer as having a hard-working but fun-loving personality.

“She would sometimes lose things in translation — even rowing commands — which would make for fun practices. But she was the type of person who seemed to be just relishing learning everything she could about America,” she said weeping as she spoke in a phone interview. “To her, life was a huge adventure.”

Catherine Campbell, Keijzer’s former roommate and rowing teammate, mourned her on Facebook. “You challenged me to be an excellent rower (even when you complained about 6 am workouts) and a lover of life,” Campbell posted. “You didn’t understand Football but, that’s ok. . .I loved blasting Mike Posner’s ‘Bow Chicka Wow Wow’ and singing loud for all to hear in Big Bird. You relentlessly pursued happiness and found it everyday.”

Keijzer’s hometown was Almelo, Netherlands, about 90 miles east of Amsterdam, according to her Facebook page. In Bloomington, she was a member of the women’s rowing team for just one year but made a big impression.

Jaclyn Riedel, 24, who was at times Keijzer’s rowing partner, said her teammates were so touched by her interest in them that they decided to take an interest in her.

“Every day after practice, we asked her to teach us Dutch words. And she did with so much happiness,” she said,

They once asked her to teach them the word for garden gnome and that was “kabouters.”

Karlijn Keijzer is shown in this undated photograph from Indiana University. (Mike Dickbernd/Indiana University)

“It made no sense, but it was so funny, and from then on wherever we went if we had a good practice we would cheer ‘kabouters, kabouters.’ If we won a game it would be ‘kabouters!’ ” Riedel said.

A speedy rower, she helped the team achieve a 14-5 record during the 2011 season.

“The thing I think about is how she never complained about her work load or how demanding rowing was,” she said. “Before practice, she would turn around and pound her chest — like ‘ROAAAR.’ To wake us all up and get into it. That meant so much when you are waking up at 5 or 6 a.m., and its just very hard work.”

Mu-Hyun Baik, associate professor of chemistry and informatics and Keijzer’s doctoral adviser, called her “a diligent researcher and a dear friend to all of us who worked with her in our research group.”

“She inspired us all with her optimism about how science will make Earth a better place,” he e-mailed in a statement.

In May, Keijzer completed her last piece of research work before catching her flight to the Netherlands for her summer vacation. She was preparing a computer simulation on bryostatin, an anti-cancer drug and a promising candidate for treating Alzheimer’s disease.

Her friends were having trouble believing she wouldn’t be coming back to Bloomington.

“When a friend called to tell me she had died, I just didn’t want to believe it” said Riedel, who’d gotten birthday wishes from Keijzer on Tuesday. “This whole thing, it’s just so tough.”

Julie Tate contributed to this report.