BY ALEXANDRA ALTER

Ask Melissa Matos why she converted to Islam, and you'll likely get an answer that spans 13 centuries. She may refer to seventh century Arabia, where Muslims believe the Prophet Mohammed received the Koran from the angel Gabriel. Or she might describe Islam's golden age in medieval Spain. Or she'll recall Sept. 11, 2001, when fear and curiosity drove her to read about Islam on the Internet.

Matos, who comes from a family of Seventh-day Adventists from the Dominican Republic, has answered the question countless times since converting to Islam in April. She now covers her hair, prays five times a day, and today will observe Ramadan, a month of fasting, prayer and reflection, which began at sundown.

''Sometimes it does get a little difficult,'' said Matos, a 20-year-old political science student at Florida International University who lives with her parents in Miramar. ``I feel alienated from my family and my old friends, but Islam is so beautiful, it's worth it. And with Ramadan, I'm just doing it by myself, just me and God.''

Though Hispanic women make up a small fraction of the nation's 6 million Muslims, those converting to Islam are exerting influence beyond their numbers, teaching Spanish-Arabic classes, forming Hispanic-Muslim organizations and distributing the Koran in Spanish.

Matos, for one, plans to organize a lecture series this semester at FIU on the religion's little-known history in Latin America, including two lectures that will be in Spanish, she said.

Some have founded support networks. Piedad, a network of Muslim women that seeks to educate Spanish-speaking communities about Islam, has more than 344 members nationally. Other groups, like the Latino American Dawah Organization , which was formed in 1997, promote the legacy of Islam in Spain and Latin America.

''It's a movement that is growing, particularly in urban areas,'' said Manuel Vasquez, a professor of religion at the University of Florida. ``It's part of the cross-fertilization that's occurring among immigrant groups.''

There are some 40,000 Hispanic Muslims in the United States, according to a spokesman for the Islamic Society of North America. The largest populations live in New York, Texas, Los Angeles, Chicago and Miami, American Muslim organizations say.

Jameela Ali, 26, became a Muslim seven years ago after she dreamed she was praying in a mosque filled with light. Her mother, who is from Peru, had converted to Islam several years before. Now her brother, 22, and sister, 21, have converted.

''You feel a much closer connection to God,'' said Ali, who lives in Pembroke Pines and teaches two other Hispanic Muslim women to read and write Arabic. ``You give up everything of your old lifestyle -- your old clothes, you're not going to clubs, you're not drinking, you're not smoking.''

Islam's growth among Hispanic women may result from the broader Muslim outreach following the Sept. 11 attacks, said Aisha Musa, an assistant professor of religion at Florida International University.

SPANISH KORANS

Sofian Abdelaziz, the director of the American Muslim Association of North America in Miami, said his group often gets requests for the Koran in Spanish. In the last several years, they've given away more than 5,000 Spanish translations of the Koran to South Florida mosques and prisons, he said.

Converts and Muslim leaders are quick to note that Muslims accept Hebrew and Christian scripture as revelation, but maintain that the Prophet Mohammed provided the complete word of God. Muslims follow the Koran, the holy book revealed to Mohammed. Islam's five central tenets include professing faith in God and his prophet, Mohammed, performing daily prayers, showing charity, fasting during Ramadan and making hajj or pilgrimage to Mecca, Islam's holy city in Saudi Arabia.

Islam spread rapidly after Mohammed's death in the seventh century and today is one of the fastest-growing religions in North America, scholars say. Hispanic converts in urban areas say it's become easier to find like-minded communities.

''It's so great to meet other Latin people because we all know each other's backgrounds,'' said Fatima Narvaez, 30, who converted in 2002 and now studies Arabic with two other Hispanic women on the weekends.

But convincing families that conversion is the way to go hasn't always been easy.

CLASHING BELIEFS

''They think I've rejected my way to salvation because I don't believe Jesus Christ is the son of God,'' Matos said of her parents, who are Seventh-day Adventists.

Roraima Aisha Kanar was raised Roman Catholic by her parents, Cuban exiles who settled in Miami in 1959. Kanar, 52, considered becoming a nun before converting to Islam at age 22. Her parents, devout Catholics, didn't want their grandchildren to be raised Muslim, she said.

''It was very hard to know that my own mother didn't respect my belief,'' said Kanar, who with her husband raised their three children as Muslims.

But others have found support from their families. Narvaez, who lives with her grandparents in Davie, was worried they wouldn't understand her new dietary practices. Islam forbids pork and meat that isn't halal, or slaughtered according to Islamic law.

''With Puerto Ricans, there's pork in everything,'' said Narvaez, who works in marketing. ``But they accommodate all my issues and cook halal food for me.''

Ali said she's renounced aspects of Hispanic culture that conflict with her beliefs, like cooking with wine or eating pork. But she still marks Christmas with her Peruvian family and cooks South American dishes.

''Islam is a way of life, but you don't suddenly have to start listening to Arabic music,'' said Ali. ``We still keep our heritage.''