The final lesson of Unit 2 explores how amino acids connect to make proteins.  The Lesson 48 PowerPoint includes the vocabulary terms of amino acid and protein.  Lesson 48 connects with Lesson 47, as amino acids are chiral molecules.  Notably, all of the 20 different amino acids in human proteins are “left-handed” (as opposed to the mirror-image “right-handed” isomers), meaning they all have the L conformation (L for laevus, Latin for “left”) rather than the D conformation (D for dexter, Latin for “right”).  Students will work in pairs to complete the Lesson 48 Worksheet, learning about the properties of amino acids and how they bind together to form proteins.  For more on the D and L convention, click on the picture below.

As noted previously, there are 20 different amino acids.  All amino acids share the same base structure of a central carbon atom bound to a carboxylic acid (-COOH), an amino group (-NH2), and a hydrogen (H).  The central carbon is also bound to an R group, with R indicating any one of the 20 different amino acid structures.  The structures each have different physical properties.  When individual amino acids link together, a polypeptide chain is formed (and a molecule of water is removed as each new amino acid is linked to the chain).  The polypeptide chain, composed of a string of amino acids, folds into a particular shape determined by the interactions of all of the amino acids.  The shape of a protein determines its function in the body.  Mr. Anderson of Bozeman Science has a fantastic video explaining the nature of proteins:

For students looking for a good review of Central Dogma (DNA > RNA > Protein > Trait), the Crash Course Biology video DNA, Hot Pockets, & The Longest Word Ever is a good resource:

Finally, for students with access to a home computer, the Fold.It website will have you folding proteins in no time!

Homework:

• Read Lesson 48 in the textbook.  Login via hs.saplinglearning.com and enter your username and password:
  • Username: wahps****s-####### (**** = first 4 letters of your last name and ####### = student number).  Remember to include the dash between s and #.
  • Password: S-####### (the S must be capitalized)
• Write notes for Lesson 48 on the Chapter 9 Notes handout.
• Work through the practice problems at the end of Lesson 48.
• Please ask questions about anything from Lesson 48 you do not yet fully understand.

We began with the Lesson 47 PowerPoint ChemCatalyst to help get students thinking about mirror images.  We then watched a short video about chirality (below):

Students then received the Lesson 47 Worksheet, working in pairs to model the compounds using the class set of molecular modeling kits.  The worksheet concluded with students hypothesizing whether L-carvone will smell like D-carvone, and then testing their hypothesis.

Class Notes

Keep Learning!

Want more?  Check out the blog post Perhaps looking-glass milk isn’t good to drink for an overview of Lewis Carroll, looking-glass milk, and L- and D-carvone.  Want more?  Joanna Shawn Brigid O’Leary from Rice University published an even more extensive investigation of how Lewis Carroll (author of Alice in Wonderland and Through the Looking Glass) weaved biochemistry into his fiction.  Her paper (available as a PDF), WHERE ‘THINGS GO THE OTHER WAY’: THE STEREOCHEMISTRY OF LEWIS CARROLL’S LOOKING-GLASS WORLD is well worth the read.  Perhaps it will even inspire students to read the book before the movie is released in theaters on May 27!

Homework:

• Read Lesson 47 in the textbook.  Login via hs.saplinglearning.com and enter your username and password:
  • Username: wahps****s-####### (**** = first 4 letters of your last name and ####### = student number).  Remember to include the dash between s and #.
  • Password: S-####### (the S must be capitalized)
• Write notes for Lesson 47 on the Chapter 9 Notes handout.
• Work through the practice problems at the end of Lesson 47.
• Please ask questions about anything from Lesson 47 you do not yet fully understand.

Entry Task

Chapter 8 concluded with the Lesson 46 PowerPoint and Lesson 46 Worksheet.  Lesson 46 brought together the various concepts needed to understand how molecules with certain properties can be detected by our noses, with our brain recognizing those molecules as having a specific smell.  The ChemCatalyst asks students to model why perfume molecules can be smelled from across a room, but paper cannot (both placed near a sunny window).

Homework:

• Read Lesson 46 in the textbook.  Login via hs.saplinglearning.com and enter your username and password:
  • Username: wahps****s-####### (**** = first 4 letters of your last name and ####### = student number).  Remember to include the dash between s and #.
  • Password: S-####### (the S must be capitalized)
• Write notes for Lesson 46 on the Chapter 8 Notes handout.
• Work through the practice problems at the end of Lesson 46.
• Please ask questions about anything from Lesson 46 you do not yet fully understand.

Entry Task

We continued our study of polarity, this time exploring how the polarity of molecules might impact our ability to smell the molecule.  Through the Lesson 45 PowerPoint, students learned that polar molecules are more likely to be detected by the nose as something with a scent although there are still polar molecules (like water) that do not smell.  Students worked in pairs to cut out the molecules in the molecules handout and used the molecules to complete the Lesson 45 Worksheet.

Class Notes:

Homework:

• Read Lesson 45 in the textbook.  Login via hs.saplinglearning.com and enter your username and password:
  • Username: wahps****s-####### (**** = first 4 letters of your last name and ####### = student number).  Remember to include the dash between s and #.
  • Password: S-####### (the S must be capitalized)
• Write notes for Lesson 45 on the Chapter 8 Notes handout.
• Work through the practice problems at the end of Lesson 45.
• Please ask questions about anything from Lesson 45 you do not yet fully understand.

Entry Task

After learning about the concepts of electronegativity and polarity in yesterday’s lesson, students learned how scientist Linus Pauling assigned electronegativity values to individual atoms as a measure of how strongly an atom attracts electrons.  The Lesson 44 PowerPoint includes a copy of the periodic table with electronegativity values for each element.  It also explains the difference in electronegativity between covalent bonds (0.5 and less), polar covalent bonds (between 0.5-2.1), and ionic bonds (greater than 2.1).  The Lesson 44 Worksheet provides students with the opportunity to calculate the electronegativity difference between two atoms in a molecule and to use that information to determine the type of bond that is present between the two atoms.

Class Notes:

Molecule Polarity Simulation:

https://phet.colorado.edu/sims/html/molecule-polarity/latest/molecule-polarity_en.html

Homework:

• Read Lesson 44 in the textbook.  Login via hs.saplinglearning.com and enter your username and password:
  • Username: wahps****s-####### (**** = first 4 letters of your last name and ####### = student number).  Remember to include the dash between s and #.
  • Password: S-####### (the S must be capitalized)
• Write notes for Lesson 44 on the Chapter 8 Notes handout.
• Work through the practice problems at the end of Lesson 44.
• Please ask questions about anything from Lesson 44 you do not yet fully understand.

Entry Task

After completing the entry task, we reviewed the results of the Graphing Practice entry tasks from the week before Winter Break.  Next, we transitioned to Lesson 43 by first watching the Crash Course chemistry video about polar and non-polar molecules:

Following along with the polar bear theme, students received copies of the Lesson 43 Worksheet and accompanying cartoon.  After reading through the cartoon and working through the worksheet, we briefly worked through parts of the Lesson 43 PowerPoint and students received a copy of the periodic table that includes the electronegativity values for each element.

Notes from class:

Homework:

• Read Lesson 43 in the textbook.  Login via hs.saplinglearning.com and enter your username and password:
  • Username: wahps****s-####### (**** = first 4 letters of your last name and ####### = student number).  Remember to include the dash between s and #.
  • Password: S-####### (the S must be capitalized)
• Write notes for Lesson 43 on the Chapter 8 Notes handout.
• Work through the practice problems at the end of Lesson 43.
• Please ask questions about anything from Lesson 43 you do not yet fully understand.

Entry Task

We kicked off 2019 with Lesson 42: Attraction between molecules.  Students received the Lesson 42 Worksheet and then we briefly reviewed functional groups and the concept of polarity.  The lab calls for students to observe the characteristics of water, acetic acid, isopropanol, and hexane (molecular structures are shown below):

Notes from the whiteboard depicting the lab setup are shown below:

Homework:

• Read Lesson 42 in the textbook.  Login via hs.saplinglearning.com and enter your username and password:
  • Username: wahps****s-####### (**** = first 4 letters of your last name and ####### = student number).  Remember to include the dash between s and #.
  • Password: S-####### (the S must be capitalized)
• Write notes for Lesson 42 on the Chapter 8 Notes handout.
• Work through the practice problems at the end of Lesson 42.
• Please ask questions about anything from Lesson 42 you do not yet fully understand.

We began class with a team-building exercise where students shared answers to the Cosmos video from yesterday.  Next, we transitioned to Lesson 41, the final lesson of chapter 7, which brings together student learning about how the olfactory system works (the way we perceive smell).

The TED-Ed video below reviews the process of how we smell:

The Lesson 41 PowerPoint includes the key vocabulary concept of receptor site theory, where students learn the importance of molecule shape in determining recognition by receptor molecules involved in sensing smell.

Work for today (+5 bonus points for finished poster, due Monday, January 7, 2019):

1. Research the molecule responsible for your favorite smell.  Example: limonene is the compound that gives orange peels their smell (CompoundChem has a huge list of aroma chemistry infographics)
2. View the molecule on MolView.
3. Research whether the olfactory receptor is known for the molecule.  A list of smell molecules and their olfactory receptors is located at OlfactionDB. For limonene, the olfactory receptors are coded for by the genes Olfr56 (mouse) and OR2V1 (human).
4. Make a poster (8.5″ x 11″ paper)!  Your poster should include:

• the name of the molecule
• the structure
• the smell
• the name of the olfactory receptor (if known)

Homework:

• Complete up to 4 different POGIL activities and earn +1 bonus point per page!  Due Monday, January 7, 2019.
• Read Lesson 41 in the textbook.  Login via hs.saplinglearning.com and enter your username and password:
• • Username: wahps****s-####### (**** = first 4 letters of your last name and ####### = student number).  Remember to include the dash between s and #.
• • Password: S-####### (the S must be capitalized)
• Write notes for Lesson 41 on the Chapter 7 Notes handout.
• Work through the practice problems at the end of Lesson 41.
• Please ask questions about anything from Lesson 41 you do not yet fully understand.