Two plant species co-occur in a prairie. Species X always occurs near species Y. However, species Y often occurs in isolation from species X and produces more seeds when alone than when growing next to species X. Which of the following interactions between species X and Y could generate this pattern?

#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:

#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: 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: 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: 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: 536

#Unit 1. Molecules and their Interaction Relevant to Biology

Glucose 6-phosphate allosterically inhibits

A) hexokinase I.

B) glucokinase.

C) hexokinase II.