Science December 1st-5th

This week we continued with photosynthosis in class. We noticed that resperation and photosynthosis work as a cycle in some ways. The starting material for each is the ending for the other. They help each other to complete their job. They are also not a cycle because new CO2 and H2O are always coming in and O2 is always leaving. We also learned that photosynthosis is like the opposite of resperation.

Thenwe talked about what happens when you have resperation without O2. It turns out that cramps are caused when there is resperation without O2. Also, when you don't have oxygen, instead of H2O being an end result, in animals lacticacid takes its place. In plants alcohol takes H2O's place. To test if resperation really could happen without O2 we put yeast, water, and sugar in a large test tube. We put a ballon at the end of the vial. If the ballon folls with air we thought, then resperation occured. An d the ballon did inflate.

We talked about DNA too. Deoxyribonucleic acid (DNA) we said is found in the nucleus or nucleoid of cells. It controls what the cell does, and how it looks. Every person, besides twins, have different DNA because each person's DNA is a combo of both of their parent's DNA. Anything born from only one parent looks exactly like that parent because there is no combo of DNA.

We wanted to see what DNA looked like. We mixed water in our mouths for 1 minute then spit it in a cup. Next we mixed with detergent, contact solution and rubbing alcohol in a vial. In fifteen minutes the result was white stringy subbstances forming in the water. The mixture had broken through the cell membrane in our cheek cells. This let the DNA out which formed the white strings. As extra credit I am going to do the same experiment with plant cells. Then we are going to look at the DNA under microscopes.