BIOL-180: Physiology Lab 2

Amphipathic

Contains both polar (hydrophilic) and non-polar (hydrophobic) regions

Semi-permeable

Some molecules can freely pass through the membrane while others cannot

Diffusion

Movement of molecules from areas of high concentration to areas of low concentration

Simple Diffusion

Small, nonpolar substances diffuse rapidly across a membrane (O₂, CO₂, steroids, fatty acids)

Facilitated Diffusion

molecules transported across a membrane by specialized protein channels and transporters

Non-penetrating Solutes

Substances that cannot cross the plasma membrane (do not penetrate the lipid bilayer)

Osmolarity

Total concentration of solutes

Tonicity

The concentration of non-penetrating solutes in a solution

Aquaporins

Protein channels that transfer water across the plasma membrane of cells

Osmosis

The net diffusion of water across a membrane

Extracellular fluid

Fluid found outside of cells

Isotonic solution

Same concentration of solutes inside and outside of cell

Hypotonic Solution

Non-penetrating solute concentration lower than the cell

Lysis

The bursting of cells

Hemolysis

The bursting of red blood cells

Hypertonic Solution

Solution contains greater concentration of solutes than cell

Crenation

the process of cells shrinking as water moves out of the cell and into the fluid with the lower water concentration

Homeostasis

Self regulation process by which a living organism maintains a stable, constant internal environment necessary for survival

Erythrocytes

Red blood cells

Hematocrit (Hct)

A test used to determine the percent of formed cells in blood

• (RBCs/RBCs+Plasma+leukocytes)

• Hct normal values: 42-52% (men), 37-47% (women)

Anemia

Hct counts below normal ranges