Embed Size (px)
Citation preview
Chapter 9 (continued)
Fermentation
glucose
2 ATP
2 NADH
2 pyruvate
2 ATP
8 NADH
2FADH2
O2 32-34 ATP
water
glycolysis
citric Acidcycle
oxidative phosphorylation
glucose
2 ATP
2 NADH
2 pyruvate
2 ATP
8 NADH
2FADH2
O2 32-34 ATP
water
glycolysis
citric Acidcycle
oxidative phosphorylation
What if there’s no oxygen?
glucose
2 ATP
2 NADH
2 pyruvate
2 ATP
8 NADH
2FADH2
O2 32-34 ATP
water
glycolysis
citric Acidcycle
oxidative phosphorylation
Then there’s nowhere for the ETC to dump its electrons.
glucose
2 ATP
2 NADH
2 pyruvate
2 ATP
8 NADH
2FADH2
O2 32-34 ATP
water
glycolysis
citric Acidcycle
oxidative phosphorylation
So there’s nowhere for NADH
and FADH2 to unload.
glucose
2 ATP
2 NADH
2 pyruvate
2 ATP
8 NADH
2FADH2
O2 32-34 ATP
water
glycolysis
citric Acidcycle
oxidative phosphorylation
So the citric acid
cycle stops.
glucose
2 ATP
2 NADH
2 pyruvate
glycolysis
But wait! It gets even
worse!
glucose
2 ATP
2 NADH
2 pyruvate
2 NAD+
glycolysis
You can’t make NADH
without a steady supply
of NAD+.
glucose
2 ATP
2 NADH
2 pyruvate
2 NAD+
glycolysis
NADH has nowhere to
dump its electrons.
glucose
2 ATP
2 NADH
2 pyruvate
2 NAD+
glycolysis
So we stop making more.
glucose
2 ATP
2 NADH
2 pyruvate
2 NAD+
glycolysis
So even glycolysis
stops.
glucose
2 ATP
2 NADH
2 pyruvate
2 NAD+
glycolysis
Is there no hope?
glucose
2 ATP
2 NADH
2 pyruvate
2 NAD+
glycolysis
There is!There’s
something else we can do.
glucose
2 ATP
2 NADH
2 pyruvate
2 NAD+
glycolysis
We can use the NADH…
glucose
2 ATP
2 NADH
2 pyruvate
2 NAD+
glycolysis
2 ethanol or 2 lactateWe can use the NADH… to turn
pyruvateinto ethanol or
lactate.
glucose
2 ATP
2 NADH
2 pyruvate
2 NAD+
glycolysis
2 ethanol or 2 lactate
That way, at least we get to keep the 2 ATP.
glucose
2 ATP
2 NADH
2 pyruvate
2 NAD+ 2 ATP
8 NADH
2FADH2
O2 32-34 ATP
water
glycolysis
citric acidcycle
oxidative phosphorylationIt’s not much, but it’s
better than nothing.
2 ethanol or 2 lactate
.
