Glycolysis
Starts all energy pathways
Why is glycolysis important even though it only makes 2 ATP?
What pathway occurs with oxygen?
Aerobic respiration
Main purpose?
Make electron carriers
Final electron acceptor?
oxygen
Why do muscles burn during exercise?
Lactate buildup
Glycolysis stops
What would happen if NAD⁺ ran out during glycolysis?
Why does fermentation happen?
Regenerate NAD⁺
What are the outputs?
NADH, FADH₂, CO₂
What is formed when oxygen accepts electrons?
water
Why can fermentation keep you alive briefly?
Keeps glycolysis running
Doesn’t require ETC
Why can glycolysis occur without oxygen?
Why is aerobic respiration more efficient?
Uses ETC
Why doesn’t Krebs make much ATP directly?
Focus is electron carriers
What creates the proton gradient?
Electron movement through complexes
Why is oxygen indirectly required for ATP production?
Keeps ETC going
Everything shuts down
If glycolysis stops, what happens to the entire cell’s energy production?
What happens to pyruvate without oxygen?
Fermentation
What must happen before Krebs starts?
Pyruvate → Acetyl-CoA
What uses the gradient to make ATP?
ATP synthase
What is the most important step for producing the MOST ATP?
ETC
A cell is alive but only producing small amounts of ATP. Which pathway is likely dominating and why?
Glycolysis (low efficiency)
Why does oxygen availability directly control how much ATP a cell can make?
Needed for ETC to keep running
Why would Krebs cycle stop if the ETC stops working?
NADH not recycled → no NAD⁺
if the proton gradient disappears, what happens to ATP production and why?
Stops (no driving force)
A runner runs out of oxygen, then oxygen returns. What happens to ATP production?