Module 3: Function of Cell Membranes

Filtration

A process in which fluid is forced through a selectively permeable membrane

Diffisuion

Net movement of particles from a place of higher concentration to a place of lower concentration due to constant spontaneous motion

Simple Diffusion

How oxygen and CO2 diffuse

Facilitated Diffusion

How glucose and ions diffuse

Osmosis

The net flow of water from one side of a selectively permeable membrane to another

In osmosis water flows from the — watery side to the — watery side

more, less

Tonicity

The ability of a solution to change the volume or pressure of a cell by osmosis

Isotonic Solution

The extracellular fluid and cytosol have the same relative concentration of solutes and there’s no net movement of water through the plasma membrane

Hypotonic Solution

The concentration of solutes in the extracellular fluid is lower the the cytosol and water moves into the cell increasing pressure until it bursts

Hemolysis

Rupturing of red blood cells

Hypertonic Solution

The concentration of solutes is greater in extra cellular fluids then the cytosol and water moves out of the cell reducing pressure and volume until it shrinks

Crenation

Water volume in the cell reducing until the cell shrinks

Hypotonic Cell

Normal Cell

Hypertonic Cell

Benedict Solution

Used to detect reduction in sugars

Iodine Solution

Tests for presence of starch

Silver Nitrate Solution

Detects salt if theres a cloudy streak theres salt

No reducing sugars

Moderate sugar level

Low Sugar (higher then green)

Traceable sugar

High Sugar Level

Water Soluble Substances Need — or — to Diffuse

Protein Chanel or Pore

Active Transport

Substances move against the gradient from low to high cincetration