Seventh Class: Ye Olde Tale Of The Theft Of Young Jerell's Ipod

In this class we figured out who stole Jerell's iPod based on the food sample they left behind.  We tested the foods: pretzels, butter, jelly, fat-free yogurt, beans, and a wet and dry sample of food the thief left behind.  From this we found which of these foods contains glucose, starch, protein, and/or lipids.  Knowing which foods had each, we then looked at what Jerell's co-workers ate for lunch.  The only food that matched the mystery substance was Jose's bean and cheese burrito.  Thus the culprit was Jose, the new guy around the joint.  Finding this out was only possible by using iodine, biuret, benedicts and sudan to test for basic elements within everyday food.

Wasn't me e se...

-Jose

Sixth Class: Cell Wall Structure

In this class we examined how diffusion and osmosis work at a cellular level. Molecules trying to get through the call wall must either be non-polar and pass through the bi lipid layer, or get "ferried" across by a protein.  Polar molecules such as H2O cannot slip all the way through the bi-lipid layer because when they reach the second layer the polarities repel and it is shot back out.  For non polar molecules that are not too large, this is no problem and they slip through without going through a protein.  For the polar molecules to get into cells, this is what they must do.  Certain proteins will accept certain molecules while others will let any molecules of the correct size pass through easily.  These proteins are scattered all over the cell wall to pick up molecules as they come in.  They serve as the GATEKEEPERS  for the cell.  The carbohydrates on cells reach out and grab connect with other cells.  Messages such as pain, are sent through the body by these connections chemically.  Thus a body of cells works together by connecting cell membranes.

Fifth Class: Diffusion Lab

In the fifth class of biology, we conducted a lab to find the effects and rules of diffusion in molecules.  As previously explained in the last blog, diffusion is the ability molecules have to move through semi-permeable surfaces.  This lab showed us that molecules can diffuse based on their size and take longer to move through thicker surfaces. In the picture on the left we placed starch in dialysis tubing and let it soak in Iodine.  The starch turned dark blue form the iodine diffusing in.  We than took some of the remaining iodine out and mixed it with benadicts, while heating it, to see that no starch escaped the tubing and the chemicals bonded to form a brown solution. The middle and rightmost pictures show how far through NaOH can soak through a "cell" of that size in 15 minutes. The last picture is simply for your enjoyment, enjoy.

Yeaaa Baby! -Adam

Fourth Class: Diffusion and Osmosis

In our fourth class we looked at the processes of Diffusion and Osmosis. Diffusion is the way molecules will exit or enter a semipermeable surface to balance the pressure on either side of the surface.  For example, when a bottle of perfume is opened, the molecules will slowly shoot out as they are bouncing all over the place.  In balloons, after a while they shrink and no longer float on their own.  This happens as helium molecules rush out of the thin material and it becomes heavier than the air around it.  Osmosis is a similar process, but is only used to describe water molecules.  In cells water molecules can move in and out through the cell wall because it is semi-permeable.  This is important especially to human life, because it is the reason we drink water.  The water enters our blood system and hydrates the blood cells.  Water can move like this due to its size and it's innate ability to balance the pressure on either side or a membrane.  Osmosis and diffusion are important in life because of their significance in the movement of molecules.

Third Class: Water -- Cohesion vs. Adhesion

In class three we looked at the properties of water: cohesion and adhesion.

Cohesion:
         Cohesion is the ability that water has to "climb" up objects like straws.  This is possible because of the way the molecules bond together they will appear to climb up the sides of glasses or straws.  The water can only go to a certain point before having to stop because it cannot support any more molecules on top.
Adhesion:
         Adhesion is the ability that water has to hold together and form a bubble shape with high surface tension.  In the lab we would drop as many droplets of water onto a penny before the surface tension would grow to great and the water would spill off the penny.  The bonds within the water lets it retain it's shape on top of the penny.
          These properties of water allow trees to get water to their leaves, let water striders run across water, and water to form symmetrical droplets in nature.