6. The NADH and FADH2 produced during the Krebs cycle pass their electrons down the 7. __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ chain to produce ATP.

The NADH and FADH2 produced during the Krebs cycle pass the electrons down  electron transport chain in the mitochondria to generate more ATP molecules

Explanation:

FADH2 stands for Flavin adenine dinucleotide and NADH stands for Nicotinamide adenine dinucleotide.

Both are created from FAD and NAD+ through reduction-oxidation reactions in the Krebs cycle during respiration as explained below:

This cycle gives off small amounts of energy in the form of adenosine triphosphate, or ATP, and produces these compounds, FADH2 and NADH. The Krebs cycle is like a wheel. Every time it makes one full rotation, energy is created and released. As you can see from the diagram, the NAD+ and FAD are brought in at key points throughout the cycle and are attached to other electrons resulting in the formation of NADH and FADH2.

This energy is then shuttled off to be used by the cell, mostly for the continuation of cellular respiration.

As they are shuttled away, these two compounds are used to move electrons into the electron transport chain, the final stage of respiration. It is in this stage that most of the energy is created and released from the mitochondria (powerhouse of the cell).

Basically the NADH and FADH2 are affixed with electrons and tranfered to the inner membrane of the mitochondria. The travel down the electron transfer chain, releasing electrons they once had. Thereby releasing alot of energy in the process