Biochemistry Lab

You haven't gone through chemistry yet, but if you want to be prepared when you do follow along here! We will build on the work we did in the lab, and provide more chances to interact with this incredibly useful branch of science. We introduced you to a lot of information in a short amount of time, so it's only natural if you didn't understand all of it. Here is where we can hopefully make sense out of any lingering questions you still may have. Again, we will need some definitions before we get started:

Atoms: The basic building blocks of matter, these tiny particles are made of protons, neutrons and electrons. The periodic table is a list of atoms discovered or created by scientists.

Molecules: A molecule is made up of bonded atoms. An example of this would be atoms of hydrogen and oxygen atoms, when combined together make a water molecule.

We'll start with the difference between physical changes and chemical changes. The example you had in the lab was dissolving table salt in water, and dissolving sugar in water.

You should go to the site HERE so we can explain what's going on when you put each of these in water and why they are different. Go to the site and click on the play button on the mini video screen. Now look at the top left corner, there are three tabs labeled "Macro", "Micro" and "Water". We will start with the second tab labeled "Micro".

Open that tab and try shaking the sodium chloride (table salt) shaker. As you add the salt, the larger green circles are the chlorine atoms, and the smaller pink circles are the sodium atoms. See how they are all bunched together? That's because they are bonded. When the sodium chloride molecule enters the water, it breaks up into ions which are atoms that have a positive or a negative charge on them. Each ion bounces around freely in water. This is called a chemical change because the sodium chloride breaks apart into it's different atoms.

Now click on the sucrose (sugar) option in the solute box. Pour some sucrose into the water. Do you see that the sucrose molecule stays together as it enters the water? The sucrose molecules stay together, they do not break up into the carbon, hydrogen and oxygen atoms like the sodium chloride did. This is then called a physical change.

If you are still curious about the other subjects we covered, please check back here, or ask one of your teachers for more information. Please know that curiosity did not kill the cat, it's a very important quality that will serve you well in all you do!