How to Read a Molecule’s Skeletal Structure

glycineSince this isn’t in the textbook, here are the rules we’ll discuss and apply in class for reading the skeletal structures of molecules.

  1. Every place where lines (which represent covalent bonds) meet, there’s a carbon.
  2. Every place where lines end, there a carbon.
  3. And those carbons have the appropriate number of hydrogens bonded to them to satisfy the Octet Rule for carbon.

Try using these rules to draw out the full molecular structure of glycine (an amino acid, a kind of molecule we’ll talk about in the next part of the course) from its skeletal structure shown here. Then click on the “Continue reading” link to check your structure with a ball-and-stick depiction of glycine.  Continue reading

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Properties of Water, redux pt. 2

What property (or properties) of water or other concepts from chapter 2 can you spot in this video? What property (or properties) of life do they relate to?

Properties of Water, redux pt. 1

With the water molecule kits, figure out the following with your peers at your table:

  • What does the magnetic attraction between these plastic renditions of water molecules represent? Why are the water molecules only attracted to each other in certain ways, in certain orientations?
  • Is the molecule with the gray sphere polar or non-polar?  Hydrophilic or hydrophobic? How can you tell?
  • What do the green and blue spheres represent?
  • How does this kit show us the relative strengths of covalent, ionic and hydrogen bonds?
  • Optional: How would you depict (a) ice, (b) liquid water and (c) steam with this model kit? 

Properties of Water

One aspect of anime that can make it so immersive is the attention to detail, whether fantastical or realistic. As we watch the beginning of the Studio Ghibli film The Secret World of Arietty, see if you can spot some of the properties of water (or other concepts) you read about in chapter 2. What kind of interaction between water molecules makes these properties possible?  Continue reading

The Elements of Life

We’ll begin our discussion of basic chemistry with this perspective from Carl Sagan on the atoms that make up living things.

Keep in mind what he says about carbon and water as we head further into chemistry. Why are these two things so important?