Question

1. where does the matter used to produce atp in the electron transport chain come from? products of glycolysis products of cellular respiration products of photosynthesis products of the krebs cycle

Explanation:

Glycolysis produces pyruvate and some electron - carrying molecules, but the main matter for ATP production in the electron transport chain comes from the products of the Krebs cycle. The Krebs cycle generates NADH and FADH₂ which donate electrons to the electron transport chain to drive ATP synthesis. Cellular respiration is a broad term and products of photosynthesis are not directly involved in the electron transport chain for ATP production in cellular respiration.

Answer:

products of the Krebs cycle