1. Hexokinase II (the isoform usually discussed in biochemistry classes as part of glycolysis) catalyzes the…

1. Hexokinase II (the isoform usually discussed in biochemistry
classes as part of glycolysis) catalyzes the first step in
glycolysis. The isoform of hexokinase that is expressed in most
tumor cells is bound to the mitochondrial outer membrane facing the
cytosol. Propose two reasons why this would be beneficial to the
tumor cell.
2. Another highly regulated enzyme in glycolysis is
phosphofructokinase (PFK1). There is evidence from some tumors that
PFK1 undergoes a posttranslational proteolysis that yields a
truncated functional enzyme (47 kD vs 85 kD) that is insensitive to
citrate and ATP. How might this work and why would it be beneficial
for a tumor cell?