How do alternative substrates like mannose and fructose enter glycolysis?

• A. Mannose is converted to mannose-6-phosphate, then to fructose-6-phosphate; fructose is converted to fructose-1-phosphate, then split into glyceraldehyde and DHAP.
• B. Mannose enters glycolysis as fructose-1,6-bisphosphate; fructose enters as pyruvate.
• C. Mannose and fructose are directly converted to glucose-6-phosphate.
• D. Mannose and fructose are converted to pyruvate before entering glycolysis.

Answer: (A)