Glycolysis Worksheet – Answer Sheet
1. Explain why the phosphate end of ATP stores potential energy.
Each of the phosphate groups is negatively charged. These negative repel each other and so they would
have less energy if they were further apart.
2. Which has more potential energy, ATP or ADP?
ATP has more potential energy than ADP since it has three negatively charged phosphates held together
vs only two in ADP.
3. Write the overall reaction for cellular respiration.
Glucose + 6 O2
6 CO2 + 6 H2O (+ energy in the form of ATP and heat)
4. What atom is known as an “electron grabber” because it attracts electrons so strongly?
oxygen
5. What is an electron transport chain?
An electron transport chain is a series of molecules that each accept an electron and then pass it to the
next molecule in the chain. Each molecule in the chain holds the electrons a little more tightly so that the
electron has less and less potential energy. A good analogy for an electron transport chain is a series of
steps that gradually allow electrons to “fall” to a lower energy level. At the bottom of the steps, oxygen
is waiting to accept the electrons and make water.
6. What atom accepts electrons at the end of the electron transport chain?
oxygen
7. What is the literal meaning of the word glycolysis?
“splitting of sugar”
8. Where in the cell do the glycolysis reactions take place? Glycolysis takes place in the cytosol (the liquid
part of the cytoplasm).
9. How many ATP are used (changed to ADP) in the first half of glycolysis? 2
10. How many ATP are made from ADP in the second half of glycolysis? 4
11. What is the net gain of ATP for glycolysis? There is a net gain of 2 ATP.
12. How many molecules of pyruvic acid are made from a single molecule of glucose? 2
13. What molecule stores the high-energy electrons (and hydrogen) removed from glucose in glycolysis?
NADH