Download Electron Transport Chain Questions

Glycolysis Worksheet
1. What is the function of glycolysis?
2. With reference to glycolysis:
a. What is the starting point?
_______________________________________
b. What is the final product?
_______________________________________
3. Where in the cell does glycolysis take place? _____________________________________
4. How many ATP are used (changed to ADP) in the first half of glycolysis? ______________
5. How many ATP are made from ADP in the second half of glycolysis? ______________
6. What is the net gain of ATP for glycolysis? ______________
7. How many molecules of pyruvate are made from one molecule of glucose? ______________
8. How many carbons make up one molecule of pyruvate? ______________
9. What is the purpose of NAD+? What type of reaction is NAD+ involved in? ______________
10. What molecule stores the high-energy electrons (and hydrogen) removed from glucose in glycolysis?
11. When fructose-6-phosphate is converted to fructose-1,6-bisphosphate, what type of reaction is this?
12. If a free phosphate group is transferred to an ADP molecule, what product is formed? What type of
reaction is this?
13. In an anaerobic environment, which set of molecules directly follow glycolysis?
14. If oxygen is present, what happens to the pyruvate molecules?
Glycolysis Worksheet – ANSWERS
1. What is the function of glycolysis? To break down a molecule of 6C glucose into two molecules
of 3C pyruvate. It also serves to produce 2 molecules of ATP for energy as well as 2 molecules
of NADH (which will go onto electron transport chain for further generation of ATP).
2. With reference to glycolysis:
a. What is the starting point?
b. What is the final product?
One molecule of 6C glucose
Two molecules of 3C pyruvate
3. Where in the cell does glycolysis take place? In the cytoplasm (cytosol) of the cell
4. How many ATP are used (changed to ADP) in the first half of glycolysis? 2 ATP are used
5. How many ATP are made from ADP in the second half of glycolysis? 4 ATP are made
6. What is the net gain of ATP for glycolysis? The net gain is 2 ATP
7. How many molecules of pyruvate are made from one molecule of glucose? 2 molecules
8. How many carbons make up one molecule of pyruvate? 3 carbon atoms
9. What is the purpose of NAD+? What type of reaction is NAD+ involved in?
The purpose of NAD+ is to serve as an electron carrier. As bonds are broken in the molecule
when it is oxidized (loses electrons and H+ ion), NAD+ collects the energy in the form of
electrons and becomes reduced to NADH (oxidation-reduction reaction). The other H+ ion goes
into the cytosol to build up the concentration gradient that helps generate ATP in the next
stage. NADH then goes on to electron transport chain to generate further ATP.
10. What molecule stores the high-energy electrons (and hydrogen) removed from glucose in glycolysis?
NADH
11. When fructose-6-phosphate is converted to fructose-1,6-bisphosphate, what type of reaction is this?
Phosphorylation (as a phosphate group is added to the molecule)
12. If a free phosphate group is transferred to an ADP molecule, what product is formed? What type of
reaction is this?
When Pi is transferred to ADP, it becomes ATP. This is called substrate-level phosphorylation.
13. In an anaerobic environment, which set of molecules directly follow glycolysis?
Lactate (lactic acid fermentation) or ethanol (alcohol fermentation)
14. If oxygen is present, what happens to the pyruvate molecules?
Aerobic respiration continues with the pyruvate molecules becoming oxidized prior to entering
Krebs cycle.