Biochemistry

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Pentose Phosphate Pathway: G6P Dehydrogenase and Malaria

BIOCHM-6S2N3J

Greater resistance to the malarial parasite has been found in the host erythrocytes of individuals deficient in glucose-6-phosphate (G6P) dehydrogenase activity, a key enzyme in the pentose phosphate pathway (PPP).

The erythrocyte membranes in these individuals appear to become leakier and rupture more readily preventing the parasite from completing its life cycle and producing toxic products.

Using your understanding of the pentose phosphate pathway and the key regulatory enzyme G6P dehydrogenase, which of the following suggests the MOST likely explanation for this resistance?

A

Low glucose-6-phosphate dehydrogenase activity leads to a decrease in ATP synthesis in the erythrocytes, basically starving the cell and parasite of needed energy.

B

Low glucose-6-phosphate dehydrogenase activity leads to a decrease in NADPH synthesis needed by the erythrocytes and parasite for anabolic metabolism.

C

Low glucose-6-phosphate dehydrogenase activity leads to a decrease in NADPH synthesis which limits protective anti-oxidant activity in the erythrocyte resulting in damaged and leaky cells.

D

Low glucose-6-phosphate dehydrogenase activity leads to a decrease in oxygen partial pressure in the erythrocytes essentially suffocating the cells and parasites.

E

Low glucose-6-phosphate dehydrogenase activity leads to a decrease in carbon dioxide in the cell effectively altering the pH and destroying both the erythrocyte and parasite.