A small amount of ATP is made in glycolysis by which of the following processes?

• A. Harnessing energy from the sun
• B. Transport of electrons through a series of carriers
• C. Transfer of electrons and hydrogen atoms to NAD⁺
• D. Attachment of a free inorganic phosphate (P_i) group to ADP to make ATP
• E. Transfer of a phosphate group from a fragment of glucose to ADP by substrate-level phosphorylation

Answer: (E)

Verified step by step guidance

1. Understand that glycolysis is the process of breaking down glucose into pyruvate, producing ATP and NADH in the process.
2. Recognize that ATP production in glycolysis occurs through substrate-level phosphorylation, not oxidative phosphorylation or photophosphorylation.
3. Identify that substrate-level phosphorylation involves the direct transfer of a phosphate group from a substrate molecule to ADP, forming ATP.
4. Note that during glycolysis, a phosphate group is transferred from a phosphorylated intermediate of glucose to ADP, resulting in ATP formation.
5. Remember that this process does not involve electron transport chains or sunlight; it is a direct chemical reaction occurring in the cytoplasm.