The Norway rat (Rattus Norvegicus), a widespread pest, was controlled for about a decade by the anticoagulant warfarin. This chemical substance, placed in food pellets, is absorbed by the intestinal tract and inhibits the clotting of blood. After a population decline for about 10 years, rat populations increased and stabilized. In one European population, as illustrated in the graph below, the percentage of rats resistant to warfarin has remained fairly stable over a number of years.

Resistance to warfarin is governed by a dominant autosomal gene, R. More than 15 percent of the resistant animals are heterozygous at this locus (Rr). The table below indicates the response to warfarin and relative reproductive fitness of individuals that are homozygous or heterozygous for the dominant gene (R). The RR individuals have a 20-fold increase in vitamin K requirement over individuals.

Fitness is a measure of the reproductive success of a particular genotype. The highest fitness is 1.00.

In a population where warfarin is no longer applied, the expectation is that the

#Question id: 536

#Unit 1. Molecules and their Interaction Relevant to Biology

Glucose 6-phosphate allosterically inhibits

A) hexokinase I.

B) glucokinase.

C) hexokinase II.

#Question id: 535

#Unit 1. Molecules and their Interaction Relevant to Biology

In some diabetic patients, glucose increases disproportionately and is unresponsive to an insulin challenge; under these conditions, how would oneʹs liver normally respond?

A) phosphorylating glucose for entry into the glycolytic pathway

B) saturating glucokinase with glucose

C) phosphorylating glucose for entry into the glycogen synthesis pathways

#Question id: 534

#Unit 1. Molecules and their Interaction Relevant to Biology

If glucose labeled with 14C in C-3 is metabolized to lactate via fermentation, the lactate will contain 14C in:

#Question id: 533

#Unit 1. Molecules and their Interaction Relevant to Biology

Glucose, labeled with 14C in different carbon atoms, is added to a crude extract of a tissue rich in the enzymes of the pentose phosphate pathway.  The most rapid production of 14CO2 will occur when the glucose is labeled in:

#Question id: 532

#Unit 1. Molecules and their Interaction Relevant to Biology

In glycolysis, fructose 1,6-bisphosphate is converted to two products with a standard free-energy change (DG'°) of 23.8 kJ/mol.  Under what conditions (encountered in a normal cell) will the free-energy change (DG) be negative, enabling the reaction to proceed to the right?

#Question id: 531

#Unit 1. Molecules and their Interaction Relevant to Biology

Glucose labeled with ¹⁴C in C-1 and C-6 gives rise in glycolysis to pyruvate labeled in: