Lecture 65

Question 1

Osmotic pressure goes _____ with an increase in Temp and increase in Solute Concentration.

Answer 1

Osmotic pressure goes UP with increase Temp and UP with increase Solute Concentration.

Question 2

Osmolarity = Concentration of compound X ____ of osmotically active species (i.e. Osmolarity of 3M NaCl = 6.)

Answer 2

Osmolarity = concentration of compound X NUMBER of osmotically active species.

Question 3

Osmolarity of Blood is often approximated as _____mOsm

Answer 3

300mOsm

Question 4

Cell bursting (e.g. Hemolysis) occurs at osmolarites of impermeant solutes outside the cell of less than ____mOsm.

Answer 4

Less than 200mOsm outside the cell.

Question 5

A solute IS permeant if its reflection coefficient (sigma) is less than ____. “Ineffective Osmoles” describes solutes whose Reflection coefficient (sigma) can be described as follows: 0 < sigma < 1. They exert a transient effect on osmotic water movement.

Answer 5

Less than 1

Question 6

If a cell shrinks, it will respond by _____ the uptake of impermeant solutes into the cell so that water will follow. Vise versa if it swells.

Answer 6

If a cell shrinks, it will INCREASING the uptake of impermeant solutes into the cell so that water will follow.

Question 7

Tonicity is determined ONLY by _______ (effective) solutes. What does this mean about their Reflection coefficient (sigma)?

Keep in mind it is the Tonicity that determines the FINAL volume change of a cell, while ______ determines the transient effect on the way to that final volume.

Answer 7

Impermeable (effective)

This means their Refection Coefficient (sigma) = 1. Remember that permeable (ineffective) solutes have 0 < sigma < 1.

Osmolarity

Question 8

In NON-isotonic conditions, ______ is the FIRST thing to flux in order to reestablish isotonicity. THEN, permeable ______ will flux, and with them ______ will follow.

Answer 8

Water

Solutes

Water