What are the primary functions of the pentose phosphate pathway? a) to provide nadph for reductive biosynthesis and for dealing with oxidative stress b) to provide nadh for reductive biosynthesis and for dealing with oxidative stress c) to provide the cells with energy d) to provide ribose-phosphate for nucleotide and nucleic acid biosynthesis

a) to provide NADPH for reductive biosynthesis and for dealing with oxidative stress

d) to provide ribose-phosphate for nucleotide and nucleic acid biosynthesis

Explanation:

During the pentose phosphate pathway, glucose 6-phosphate is oxidized into pentose phosphates. This pathway uses NADP as an electron acceptor and reduces it into NADPH. The products of this pathway, the pentose phosphates are used by the cells to synthesize nucleic acids (DNA and RNA). The pentose phosphates are also used for the synthesis of nucleotides and coenzymes such as NADH, FADH2, etc.

These synthetic pathways are particularly occurring at a higher rate in the rapidly dividing cells such as the cells of bone marrow, skin. The NADPH formed during this pathway is used by cells as an electron donor for the reactions of reductive biosynthesis. Some of these pathways are the synthesis of fatty acids, cholesterol and steroid hormones. NADPH is also involved in scavenging reactive oxygen species such as oxygen radicals. These ROS are responsible for oxidative stress.