Mamie Moy was born in 1929 in San Antonio, Texas. Her parents were first-generation immigrants from the Toishan Province of China, her mother having arrived just the year before she was born. Her father owned a grocery store in the East Side of San Antonio, as did her uncle, for whom she worked during the summers. In 1948, her father relocated to Houston to open a grocery store in the Heights. Mamie attended public elementary and middle school in San Antonio. She then attended the private high school Incarnate Word Academy (now Incarnate Word High School). She studied for one year at Incarnate Word College before transferring to the University of Texas at Austin to complete a degree in chemistry. After briefly working in the industry, she decided to pursue graduate studies at the University of Houston in 1950. She has been there ever since—first as a Master's student and T.A., then as a faculty member. As a professor of chemistry at U of H, she has revitalized and expanded the graduate program, and she has been active in National Chemistry Week and other outreach programs geared towards children. She has also served on several committees of the American Chemical Society and the Engineering, Science, and Technology Council of Houston, and she has served as the Regional Director of the Associated Chemistry Teachers of Texas. In addition to these academic endeavors, she has also served on the board of the YWCA and the Institute of Chinese Culture.