Question

1. You isolate an enzyme from the human stomach to test its activity. In order to measure optimal enzyme function, which of the following laboratory conditions should you use in the experimental reactions?

   	a.	Solutions with a pH ~2
   	b.	Reaction temperature close to normal body temperature (98.6°F)
   	c.	Include substrates for which the enzyme has high affinity
   	d.	Include high concentrations of substrate
   	e.	All of the above

2. In glycolysis, glucose-6-phosphate (G-6-P) is converted to fructose-6-phosphate (F-6-P). Which of the following statements about this reaction is true?

   	a.	G-6-P is a hexose, whereas F-6-P is a pentose
   	b.	ATP is spent to form F-6-P
   	c.	ATP is generated in the formation of F-6-P
   	d.	A 5-point monosaccharide ring structure is formed, allowing for the addition of a second phosphate group in the subsequent step
   	e.	All of the above are correct

3. You are conducting a plant growth experiment in a research laboratory. Prior to setting up your experiment, you notice that ~25% of the seed coats appear damaged. You plant them anyway, but notice that ~25% of your plants fail to germinate. All of the plants have been watered regularly, and have received adequate light. What is the most likely cause of the lack of germination?

   	a.	The hypocotyls were damaged
   	b.	The cotyledons were damaged
   	c.	The radicles were damaged
   	d.	A mutation that interfered with asexual reproduction
   	e.	All of the above likely occurred

Answer 1

Ans. 1

All the 4 options are correct. Stomach has acidic conditions due to release of HCl. Therefore stomach enzymes like pepsin has its optimum pH = 2.2

So for stomach enzymes to work optimally, low pH , close to 2 and optimum temperature close to body temperature. 98.6°F is required besides high concentrations of high affinity enzymes.

Ans. 2 only option D is correct.

Aldose sugar is converted into ketose sugar with 5 point monosaccharide ring structure which facilitates the second phophosylation in next step.

Ans. 3 option b is correct.

Cotyledons are the first part of plant to emerge from seeds. They are seed leaves and provide nutrition to the plant.