Energy Production Fatty Acid Oxidation:
In the fatty acid spiral, there is only one reaction which
directly uses ATP and that is in the initiating step. So this
is a loss of ATP and must be subtracted later.
A large amount of energy is released and restored as ATP during
the oxidation of fatty acids. The ATP is formed from both the
fatty acid spiral and the citric acid cycle.
Connections to Electron Transport and ATP:
One turn of the fatty acid spiral produces ATP from the interaction
of the coenzymes FAD (step 1) and NAD+ (step 3) with
the electron transport chain. Total ATP per turn of the fatty
acid spiral is:
Transport Diagram - (e.t.c.)
Step 1 - FAD into e.t.c. = 2 ATP
Step 3 - NAD+ into e.t.c. = 3 ATP
Total ATP per turn of spiral = 5 ATP
In order to calculate total ATP from the fatty acid spiral,
you must calculate the number of turns that the spiral makes.
Remember that the number of turns is found by subtracting one
from the number of acetyl CoA produced. See the graphic on the
Example with Palmitic Acid = 16 carbons = 8 acetyl groups
Number of turns of fatty acid spiral = 8-1 = 7 turns
ATP from fatty acid spiral = 7 turns and 5 per turn = 35 ATP.
This would be a good time to remember that single ATP that
was needed to get the fatty acid spiral started. Therefore subtract
NET ATP from Fatty Acid Spiral = 35 - 1 = 34 ATP