Glycolysis
Where in the cell does glycolysis occur
cytoplasm
Where in the mitochondrion does the Krebs cycle occur?
Matrix
Where does the ETC occur?
(Inner mitochondrial membrane/cristae
In animals, pyruvate is converted into what end product?
Lactate
How many ATP are produced from one glucose molecule in aerobic respiration
32 ATP
How many ATP molecules are net produced per glucose in glycolysis?
2
How many CO₂ molecules are released per glucose in the Krebs cycle?
4
Which complex in the ETC pumps protons and transfers electrons from NADH?
complex 1
Which enzyme catalyzes the conversion of pyruvate to lactate?
(Lactate dehydrogenase, LDH
How many ATP are generated directly in the Krebs cycle per turn?
1
Which enzyme catalyzes the phosphorylation of fructose-6-phosphate?
(Phosphofructokinase, PFK)
Name one enzyme in the Krebs cycle that produces NADH.
Isocitrate dehydrogenase, malate dehydrogenase, or α-ketoglutarate dehydrogenase
Why does FADH₂ yield fewer ATP than NADH?
(FADH₂ donates electrons at Complex II, bypassing Complex I, so fewer protons are pumped.
In yeast, what are the two products of anaerobic respiration?
Ethanol + CO₂
For each NADH entering the ETC, how many ATP are produced
2.5
What happens to NAD⁺ during glycolysis?
It is reduced to NADH
What is the role of oxaloacetate in the Krebs cycle
It combines with acetyl-CoA to form citrate, regenerating the cycle
Name the enzyme that synthesizes ATP in the ETC
ATP synthase
Why is NAD⁺ regeneration important in anaerobic respiration?
It allows glycolysis to continue producing ATP in the absence of oxygen
For each NADH entering the ETC, how many ATP are produced
32
Explain why glycolysis is considered an ancient pathway.
It occurs in the cytosol without requiring oxygen or organelles; conserved across organisms.
Compare substrate-level phosphorylation and oxidative phosphorylation in the Krebs cycle.
SLP directly produces 1 ATP (or GTP) per turn; oxidative phosphorylation indirectly yields ATP via NADH/FADH₂ in the ETC.
Explain chemiosmosis in oxidative phosphorylation.
Proton gradient across inner membrane drives protons through ATP synthase, phosphorylating ADP to ATP
Compare anaerobic respiration in animals vs yeast.
Animals: pyruvate → lactate, no gas released; Yeast: pyruvate → ethanol + CO₂. Both yield 2 ATP and regenerate NAD⁺.)