Glycolysis Groundwork
Where in the cell does glycolysis take place?
Cytoplasm
Where in the cell does the Krebs cycle occur?
Mitochondrial matrix
What is it called when there is a buildup of H+ ions in the intermembrane space?
concentration/ ion gradient
What is fermentation?
An anaerobic process that allows ATP production without oxygen
What does ATP stand for? How many phosphate groups does it have?
Adenosine Triphosphate, 3 phosphate groups
Why is glycolysis considered anaerobic?
What molecule enters the Krebs cycle from glycolysis?
Pyruvate (converted into Acetyl-CoA)
Where is the electron transport chain located in eukaryotic cells?
Inner mitochondrial membrane
Give an example of something that does alcoholic fermentation?
yeast, bread, wine, beer, etc.
Explain how ATP is generated by ATP synthase.
How many ATP are invested and how many are produced in glycolysis?
2 invested, 4 produced, net gain of 2 ATP
How many CO₂ molecules are released from one turn of the Krebs cycle (include prep step)?
3 CO₂ per turn
How do NADH and FADH₂ contribute to the ETC?
They donate high-energy electrons that power proton pumps
Compare what is produced by alcoholic fermentation and lactic acid fermentation.
Alcoholic fermentation produces ethanol and CO₂; lactic acid fermentation produces lactic acid
How many ATP are produced from one glucose molecule in aerobic respiration (approximate)?
36 - 38 ATP
What is the starting materials (reactants) of glycolysis?
Glucose, ATP, NAD+
Identify two electron carriers produced during the Krebs cycle.
NADH and FADH₂
What role does oxygen play in the electron transport chain?
Final electron acceptor, forming water
How does fermentation continue in a cyclical process?
It regenerates NAD⁺ so glycolysis can continue producing ATP
How is energy efficiency different between aerobic and anaerobic respiration?
Aerobic yields ~18x more ATP per glucose than anaerobic
Predict what would happen to cellular respiration if glycolysis did not occur.
No pyruvate would be produced, so the Krebs cycle and ETC could not proceed, halting ATP production
Explain how the Krebs cycle connects to other cellular processes.
It breaks down pyruvate from glycolysis and then supplies energy carriers (NADH and FADH2) for the ETC.
Write out the 5 steps of the ETC.
1. NADH delivers e to ETC, brings H in
2. Repeat with FADH2
3. Buildup of H+ in intermembrane space
4. H+ ions diffuse through ATP synthase, ATP made
5. Oxygen comes in and accepts the H+ and e- to make H2O
Evaluate the advantages and disadvantages of fermentation vs. aerobic respiration.
Advantage: quick ATP without oxygen; Disadvantage: much less efficient (2 ATP vs. ~36 ATP per glucose)
Construct an argument for why multicellular organisms rely on aerobic respiration instead of fermentation for most of their energy.
They require large, sustained amounts of ATP to power growth, movement, and complex functions that fermentation alone could not provide