Chapter 4, Problem 1E

Summary Introduction

Introduction:

Transport through a cell membrane is the movement of ions and molecules. It could be through passive diffusion or active transport. Sometimes, the molecules will show movement due to their net thermal motion. This movement is from an area of its higher concentration to an area of its lower concentration. The net force driving for these molecules is a chemical driving force. It drives them down the concentration gradient.

Answer to Problem 1E

Solution:

The correct answer is option (e) potassium ions and proteins are both located in greater concentration inside cells.

Explanation of Solution

Explanation/justification for the correct answer:

The correct option (e) potassium ions and proteins are both located in greater concentration inside cells. Potassium ions (K⁺) is more concentrated inside the cell than outside. Because the cell has more permeability for these ions along with the proteins. While Na²+ is more commonly concentrated outside the cell than inside. Hence, the option (e) is correct.

Explanation for the incorrect answer:

Option (a) potassium ions. These are present in more concentration inside the cell but along with the proteins. Hence, option (a) is incorrect.

Option (b) sodium ions. The cell is very less permeable to these sodium ions. So, these are present in more concentration outside the cell than inside. Hence, option (b) is incorrect.

Option (c) proteins. These are present but along with the potassium ions inside the cell. Hence, option (c) is incorrect.

Option (d) potassium and sodium ions are both located in greater concentration inside cells. The sodium ions are present in a large concentration outside the cell. Hence, option (d) is incorrect.

Conclusion

Thus, potassium ions and proteins are both located in greater concentration inside cells. Because the cell has more permeability for these ions along with the carrier proteins. Hence, option (e) is correct.