Cytosolic NADH
A) Enters the mitochondrial matrix through a countertransport mechanism
B) Enters the mitochondrial matrix by active transport
C) Enters the mitochondrial matrix by passive transport
D) Enters the m itochondrial matrix by osmosis
E) NADH does not cross the inner mitochondrial membrane

Question

Quizplus · Accepted Answer

NADH cannot directly cross the inner mitochondrial membrane due to its impermeability to NADH. Instead, its electrons are transferred into the mitochondria through shuttle systems like the malate-aspartate shuttle or the glycerol phosphate shuttle, allowing for the indirect entry of the reducing equivalents into the mitochondrial electron transport chain.