MDCAT Biology MCQ #698

In the Calvin cycle, a five-carbon sugar acts as a CO2 acceptor. Which sugar is this, characterized specifically as a keto-sugar?

MDCAT Biology MCQ #698

  1. Question 1

    Q1. In the Calvin cycle, a five-carbon sugar acts as a CO2 acceptor. Which sugar is this, characterized specifically as a keto-sugar?

    • A) Ribose
    • B) Glucose
    • C) Ribulose
    • D) Fructose

    Answer: Ribulose

    Explanation: Ribulose is a ketopentose, whereas ribose is an aldopentose. Glucose is tempting as a common sugar, but it is a hexose, not a pentose.