The video explains the glycerol phosphate shuttle, a mechanism that allows NADH from glycolysis to contribute to ATP production despite the mitochondrial inner membrane's impermeability to NADH. The shuttle transfers protons and electrons from NADH to dihydroxyacetone phosphate, forming glycerol 3 phosphate, which is then converted back, transferring electrons to FAD, forming FADH2. This process ultimately leads to ATP production via the electron transport chain. The video also compares this process to NADH from the TCA cycle, highlighting differences in ATP yield due to the entry point in the electron transport chain.

Why is the glycerol phosphate shuttle necessary for cellular respiration?

• To transport glucose into the mitochondria

• To convert NADH to ATP directly

• To produce more NADH in the cytosol

• To allow NADH from glycolysis to enter the mitochondria

Which enzyme is responsible for converting dihydroxyacetone phosphate to glycerol 3 phosphate?

• ATP synthase

• Cytochrome C oxidase

• Flavoprotein dehydrogenase

• Glycerol-3-phosphate dehydrogenase 1

What is the role of FAD in the glycerol phosphate shuttle?

• It converts glucose to pyruvate

• It pumps protons across the mitochondrial membrane

• It is reduced to FADH2, carrying electrons and protons

• It acts as a substrate for ATP production

How many ATP molecules are produced from NADH generated in glycolysis via the glycerol phosphate shuttle?

• 1.5 ATP

• 4 ATP

• 3 ATP

• 2.5 ATP

What is the total number of protons pumped into the intermembrane space by NADH from the TCA cycle?

• 6 protons

• 8 protons

• 10 protons

• 12 protons

Which complex in the electron transport chain does NADH from the TCA cycle enter?

• Complex III

• Complex II

• Complex IV

• Complex I

What is the sequence of proton pumping across the complexes for NADH from the TCA cycle?

• 4, 2, 4

• 2, 4, 4

• 4, 4, 2

• 2, 2, 4