Colloidal Chemistry and Biological Systems

Colloidal chemistry and biological system

Types of mixture Solution: Is define as a homogenous mixture with uniform properties throughout. In true solution the solute cannot be isolated from the solution by filtration ,the particle size of the solute is about the same as that of solvent, and solvent and solute pass directly through the filter paper.

Properties of solution 1-contain small particles (ions or molecules) 2-Transparent. 3-Do not separate. 4-Cannot be filtered. 5-Do not scatter light.

Suspensions: is cloudy and heterogeneous mixture. The particles are larger than 10,000 Angstroms which allows them to be filtered. If a suspension is allowed to stand the particles will separate out.

Properties of suspension 1-Have very large particles. 2-Settle out. 3-can be filtered. Examples :blood platelets, muddy water, and Calamine lotion.

Colloid: Colloids are homogenous mixture that do not separate or settle out. its intermediate between a solution and suspension. Colloidal particles are small enough to pass through filters but too large to pass through semi permeable membranes. A hydrocolloid can simply be defined as a substance that forms a gel when it comes in contact with water. Such substances include both polysaccharides and proteins .

Properties of colloid 1-Have medium size particles.cannot be filtered. 2-can be separated by semi permeable membranes. 3-scatter light Examples of colloids include protein starch Blood plasma

A mixture that has solute particles that do not settle out, but are too large to pass through a semipermeable membrane is called a 1) solution. 2) colloid. 3) suspension.

osmosis Is the movement of solvent from dilute solution to a more concentrated solution through a semi permeable membrane In osmosis water (solvent) flows from the lower solute concentration into the higher solute concentration. The concentrations of the two solutions become equal with time.

Osmosis Semipermeable membrane Concentrated Sln Dilute Sln Cl- Na+ Solvent move Cl- Na+ Cl- Na+ Solvent Tries to dilute the Concentrated sln

Osmotic pressure The amount of pressure required to just stop the osmosis. Equal to the pressure that would prevent the flow of additional water into the more concentrated solution. greater as the number of dissolved particles in the solution increases.

A semipermeable membrane separates a 10% sucrose solution A from a 5% sucrose solution B. If sucrose is a colloid, fill in the blanks in the statements below. 1. Solution _A___ has the greater osmotic pressure. 2. Water initially flows from _B__ into __A_. 3. The level of solution _B___will be lower

Osmotic pressure of the blood Blood Osmotic Pressure: Is the osmotic force (water concentration gradient) which is the result of differences in water concentration between plasma and interstitial fluid.

Isotonic solution Isotonic solution : A solution that has the same salt concentration as cells and blood. Isotonic solutions are commonly used as intravenously infused fluids in hospitalized patients is known as a physiological solution . 5.0% glucose or 0.90% NaCl is used medically because each has a solute concentration equal to the osmotic pressure of red blood cells.

Hypotonic solution Has a lower osmotic pressure than red blood cells. Has a lower concentration than physiological solutions. causes water to flow into red blood cells. causes hemolysis: RBCs swell and may burst.

Hypertonic solution Has a higher osmotic pressure than RBCs. Has a higher concentration than physiological solutions. causes water to flow out of RBCs. cause crenation: RBCs shrinks in size.

Solution Types Isotonic Concentration is same on both sides. Red blood cell & plasma Hypertonic Concentration greater outside crenation - water leaves cell Hypotonic Concentration greater inside hemolysis - cell swells & ruptures

indicate if each of the following solutions is 1) isotonic 2) hypotonic 3) hypertonic. A.____ 2% NaCl solution B.____ 1% glucose solution C.____ 0.5% NaCl solution D.____ 5% glucose solution

Osmosis and IV solutions Isotonic Normal Saline (NS) = 0.9% NaCl 5% Glucose Sln Used to replace body fluids Hypertonic Used to draw water from tissue To reduce swelling Hypotonic Used to rehydrate tissue

What happen to RBC when placed in the following solution 1) not change 2) hemolyze 3) crenate. A._1_ 5% glucose solution B._2_ 1% glucose solution C._2_ 0.5% NaCl solution D._3_ 2% NaCl solution

Dialysis Is the movement of small particles and water through a semi permeable membrane. The fluid of the body undergo dialysis by the membranes of the kidneys, which remove waste material ,excess salts, and water.

Dialysis Membrane w/ bigger holes than osmosis Concentrated Sln Dilute Sln Cl- The process where solvent and other small molecules can pass through a membrane. Na+ Cl- Solvent & small particles move Na+ Cl- Na+

Dialysis of patients is accomplished using one of two methods. Hemodialysis Removal of soluble substance and water from the blood by diffusion through a semi-permeable membrane. Arterial blood is passed to the dialyzer body using for Purification ,it is then returned to the a vein. Peritoneal dialysis The cycling of sterile dialysis fluid in and out of the peritoneal cavity.