The Week of 11/30-12/4/09

This week in science, we learned about products and reactants. Here are their meanings:

Reactant- What we use or the ingredient we start with.

Product- The end

Also we learned the following statements:

• To grow, plants need more CO2
• Plants CAN take in oxygen
• The product of photosynthesis is reused as the reactant in photosynthesis
• The reactant of photosynthesis is reused as the product in respiration.
• The respiration formula is 6CO2+6H2O+light --> C6H12O6+602
• Glucose is C6H12O6

Plus we learned about fermentation:

Fermentation- Respiration without oxygen.

Also, the two kinds of respiration was a part of our discussion. There is anaerobic respiration and aerobic respiration.

Anaerobic means without air because an means without and aero means air.

Aerobic is first respiration we learned about because the first one included air.

Another fact we learned was that bio means living.

This week, we did an experiment too. This experiment was about yeast and sugar water. Here is what we did:

We put yeast in a tube and put sugar water inside with it. We filled it up so that there was no oxygen. Then, we put the cap on and shook it. We then waited for a day to see what would happen. The result of our experiment was that alcohol was starting to be produced. We sniffed it and many classmates inputted that it smelled like wine.

We also made up explanations for why fermentation is different from respiration because respiration produces energy and fermentation produces alcohol.

I also did some extra credit work for science. The question was:

Why do we look at blood during crime scenes if the red blood cells don't have a nucleus?

The answer I found was that the white blood cells are the part of the blood that gives it DNA, or Deoxyribonucleicacid.

This turns out to be:

De-Two

Oxy- Oxygen

Ribo- Sugar

Nucleic- Nucleus

Acid- Good Acid

On the board we also put up the following facts:

• Mitochondria- Respiration
• Chloroplasts- Photosynthesis
• Cell Wall- Structure
• Cell Membrane- Lets stuff in and out
• Vacuole- Storage
• Nucleus- Stores DNA

I noted that DNA is identifies a person and gives them heredity.

We did another experiment in class using lysus solution and our cheek cells. We gargled water then spit it into a cup and poured that into a tube. Then, we added lysus solution and started "swirling" our mixture. Either before or after that, we put another liquid inside the tube and swirled. If you did it right, the DNA would appear to be floating in the solution.

On Friday, we tried to describe DNA (we also ended up putting some prior knowledge into the mix), and here is what the class came up with:

• Looks like a tornado- kind of spiraled
• Nucleus- where it is stored
• Doesn't dissolve in alcohol
• Like a twisted ladder
• Large molecule

Mr. Finley then told us some very important information about DNA. Here is a picture to explain his description.

There is not just one helix (twist) but two. They are connected by base pairs, which are also two. There is also a back bone. Each helix actually has two of these back bones. They are made out of sugar.

That is what we did this week in science.