1 The E coli phosphotransferase system transports glucose in

1. The E. coli phosphotransferase system transports glucose into the cell by:

A. serving as a carrier protein that pumps glucose into the cell in an energy-dependent manner against its concentration gradient.

B. serving as a carrier protein that pumps glucose into the cell in an energy-independent manner against its concentration gradient.

C. keeping levels of intracellular glucose very low by efficiently phosphorylating intracellular glucose in an energy-dependent set of reactions.

D. keeping levels of intracellular glucose very low by efficiently phosphorylating intracellular glucose in a set of spontaneous reactions.

E. none of the above.

2. The cytoplasmic membrane is a

A. highly selective permeability barrier of the cell.

B. primary structure that maintains the shape of the cell.

C. source of nutrient production.

D. structure which identifies a cell as eukaryotic or prokaryotic.

E. none of the above

3.  Light will be __________________ when it interacts with an object that is smaller than the light\'s wavelength.

A) refracted.

B) reflected

C) absorbed.

D) scattered.

e) transformed

Solution

1. Option C is the correct answer. This process chemically alters the glucose by phosphorylation in an energy dependent manner. This way glucose enters the cell and is then phosphorylated to form glucose -6- phosphate. This change maintains the concentration gradient and allows more glucose to flow into the cell. As glucose -6- phosphate is unable to move out of the cell. Thus intercellular levels increase and intracellular level remains low.