Question

Let's say there is an I.V. solution composed of 75% dextrose in 0.3% NaCl. If you put a human cell into this solution, what would you predict the tonicity to be?

a) Hypotonic

b) Hypertonic

c) Isotonic

d) Hyperosmotic

Answer 1

A 75% dextrose solution in 0.3% NaCl is hypertonic relative to a human cell, causing water to leave the cell and potentially leading to cell shrinkage or crenation.

Step-by-step explanation:

If we're looking at a solution composed of 75% dextrose and 0.3% NaCl (sodium chloride), we are looking at a hypertonic solution with regards to a human cell. This is because the solution has a higher concentration of solutes compared to the inside of a human cell. This would lead to water leaving the cell to attempt to dilute the extracellular fluid, consequently causing the cell to shrink, a process known as crenation.

Comparatively, typical isotonic solutions for cells consist of 0.9% NaCl or 5% glucose. Since the provided solution has a much higher concentration of dextrose, it is much more concentrated than an isotonic solution and would result in a hypertonic environment for the cell.