Malic Enzyme Makes NADPH

The video tutorial discusses two main reactions in humans that produce NADPH: the pentose phosphate pathway and the malic enzyme reaction. The pentose phosphate pathway is an oxidative process that generates significant amounts of NADPH. The malic enzyme takes malate from the TCA cycle and performs oxidative decarboxylation to produce NADPH and pyruvate. This process is similar to the action of isocitrate dehydrogenase. NADPH is crucial for biosynthetic pathways, including amino acid and nucleotide synthesis. The tutorial highlights the importance of alternative NADPH production methods that do not rely heavily on glycolysis.

Which pathway is primarily responsible for producing a significant amount of NADPH in humans?

• Glycolysis

• Pentose phosphate pathway

• Krebs cycle

• Electron transport chain

What is the role of the malic enzyme in the TCA cycle?

• It reduces NAD+ to NADH

• It converts pyruvate to acetyl-CoA

• It oxidatively decarboxylates malate to pyruvate, producing NADPH

• It synthesizes ATP from ADP

Which enzyme is mechanistically similar to the malic enzyme?

• Isocitrate dehydrogenase

• Succinate dehydrogenase

• Pyruvate dehydrogenase

• Citrate synthase

Why is NADPH crucial in biosynthetic pathways?

• It transports oxygen in the blood

• It is a precursor for glucose

• It provides energy for muscle contraction

• It acts as a reducing agent in biosynthesis

What is an advantage of the malic enzyme in NADPH production?

• It requires less oxygen

• It does not divert glucose from glycolysis

• It produces more ATP

• It increases the rate of glycolysis