Chemistry LibreTexts - Carbohydrates
The Medical Biochemistry Page - Chemistry of Carbohydrates
Introduction.
Virtual Textbook of Organic Chemistry - CarbohydratesExcellent comprehensive tutorial on basic carbohydrate chemistry and nomenclature. For the MCAT, you need to be comfortable navigating this material, but don't panic and try to memorize every structure unless you really want to.
Kimball's Biology Pages - CarbohydratesThe Medical Biochemistry Page - Chemistry of Carbohydrates
Good brief survey of the main concepts.