CLEP Biology Molecular & Cellular Biology 4

Question 1

What is the net gain of ATP molecules per glucose molecule during glycolysis alone?

Accepted Answer

2 ATP

Answer

Glycolysis yields 4 ATP but consumes 2 ATP in the investment phase, resulting in a net gain of only 2 ATP per glucose.

Question 2

Which of the following correctly describes the central dogma of molecular biology?

Accepted Answer

DNA → RNA → Protein

Answer

The central dogma states that genetic information flows from DNA to RNA via transcription and then from RNA to protein via translation.

Question 3

Which type of bond holds the two strands of a DNA double helix together?

Accepted Answer

Hydrogen bonds

Answer

Hydrogen bonds between complementary base pairs (A-T and G-C) hold the two antiparallel strands of DNA together.

Question 4

Sodium-potassium (Na⁺/K⁺) ATPase pumps maintain membrane potential by moving ions how?

Accepted Answer

3 Na⁺ out and 2 K⁺ in per cycle

Answer

The Na⁺/K⁺ ATPase expels 3 sodium ions out of the cell and imports 2 potassium ions per ATP hydrolyzed, creating an electrochemical gradient.

Question 5

Which cellular structure packages and modifies proteins for secretion?

Accepted Answer

Golgi apparatus

Answer

The Golgi apparatus receives proteins from the ER, modifies them (e.g., glycosylation), sorts, and packages them into vesicles for secretion.

CLEP Practice Test