Splitting sugar for quick energy

Science · Organisms & Life Processes · ages 16-18

Name ______________________ Date ____________

What is the net yield of glycolysis per glucose?
- 4 ATP plus 4 reduced NAD
- 2 ATP plus 2 reduced NAD
- No ATP at all
Where does glycolysis happen?
- In the mitochondrial matrix
- In the nucleus
- In the cytoplasm
Glycolysis needs oxygen to run.
Circle one: True False
What is removed from pyruvate in the link reaction, and where?
- Water, in the cytoplasm
- Carbon dioxide, in the mitochondrial matrix
- Oxygen, in the nucleus
Why does glycolysis spend two ATP before it makes any?
- Priming for a bigger payoff
- To push glucose into mitochondria
- To use up spare energy
Per glucose, how many times does the link reaction run, and what does it give?
- Twice, giving two carbon dioxide and two reduced NAD
- Once, giving one ATP
- Four times, giving four ATP
A student says each glucose nets four ATP from glycolysis. What is wrong?
- Nothing, four is the net gain
- The payoff phase makes no ATP
- The net is two
A muscle cell runs short of oxygen. Why does glycolysis keep going?
- It moves into the mitochondria
- Fermentation recycles NAD
- It stops needing glucose

Answer key

For grown-ups. Fold this page away before handing over the rest.

2 ATP plus 2 reduced NAD · Four made minus two spent leaves two, plus two reduced NAD.
In the cytoplasm · It runs in the cytoplasm, so no mitochondria are needed.
False · It runs in the cytoplasm with no oxygen involved.
Carbon dioxide, in the mitochondrial matrix · In the matrix, pyruvate loses carbon dioxide and becomes acetyl CoA.
Priming for a bigger payoff · Priming splits glucose into pieces that pay back more.
Twice, giving two carbon dioxide and two reduced NAD · Two pyruvates mean two passes through the link step.
The net is two · Gross payoff is four, but the entry fee leaves two.
Fermentation recycles NAD · Recycled NAD keeps the cytoplasmic pathway spinning.