Question

1. nadh and fadh₂ release electrons to the

______________________________ pathway.

1. h+ is pumped from the matrix into the ______________________

space (hint: this happens at 1,2,3).

1. h+ is also moved from the intermembrane space back to the

______________ of the mitochondria through the enzyme
______________________ (hint: enzymes have an –ase ending).

1. atp synthase adds a ______ to adp to make atp.
2. the etc occurs in the ______________________ (hint:

organelle).

Explanation:

1. NADH and FADH₂ are electron carriers that donate electrons to the electron transport chain (ETC) pathway.
2. In the ETC, protons (H⁺) are pumped from the mitochondrial matrix into the intermembrane space at complexes I, II, III.
3. The proton gradient drives H⁺ back into the mitochondrial matrix via ATP synthase, an enzyme with the -ase ending.
4. ATP synthase catalyzes the addition of a phosphate group to ADP to form ATP.
5. The electron transport chain (ETC) is located within the mitochondria, specifically in its inner membrane, but the organelle itself is the mitochondria.

Answer:

1. electron transport chain (or ETC)
2. intermembrane
3. matrix; ATP synthase
4. phosphate group (or inorganic phosphate/Pi)
5. mitochondria (inner mitochondrial membrane is also precise, but the hint specifies organelle so mitochondria)