In Class Feb. 24th: fatty acids

Fish_oil_softgelRecently, “omega-3s” have received a lot of positive attention. Some are contained in the capsule shown here.

  • Of the molecules we’ve seen in chapter 3, what kind of molecule is an “omega-3”?
  • Is the contents of the capsule shown solid or liquid at room temperature? Why?
  • Is an “omega-3” soluble in water?
  • Where in the body is it found after some after ingestion? Why does that make sense based on what you know about the kind of molecule it is?

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Due Feb. 29th: Chemistry in Bees

Read pages 32-33, 48-49, and 64-65 in The Bee: A Natural History for some background information.

Please answer the questions below and send your responses to LesleyBioHomework@gmail.com by 9pm on Monday Feb 29th with the subject line “Chemistry in Bees”.

  1. In what ways can you relate your knowledge of chemistry to bees?
  2. What is going on in the photo below? What key terms learned in class can you incorporate in your thoughts? What about the information learned from the few pages in the book listed above?
    Santa Barbara, California, USA --- Honey bee hovering near blue-eyed grass flower --- Image by © Ralph Clevenger/Corbis
  3. Depending on the different levels of glucose and fructose, the amount of time it takes for honey to crystallize varies. Why do you think honey crystallizes? What do you think happens to the molecules when it does?
  4. Two beekeepers were analyzing their honey. The honey from one hive has a pH of 4, while the other has a pH of 6.  Is their honey acidic or basic? Which honey has more hydrogen ions? How much more?
  5. When nectar is turned into honey, the enzyme invertase splits sucrose into glucose and fructose. What is the name of the reaction that occurs?
  6. Pollen is collected when bees are out foraging for nectar. Bees will groom pollen off of their hairs and compact them onto their legs using a small amount of nectar. To collect pollen, beekeepers use pollen traps which force the bees to enter their hives through smaller holes that knocks the pollen off their legs. Based on this information, what type of bond or intermolecular force allows pollen to cling onto bees?
  7. Beeswax is used throughout the hive. The bees shape it into the hexagonal shape that we know. One way it is used is to fill and cap honey, so it can be used at a later time. This is stored as such to prevent drips and fermentation. From this information, is beeswax hydrophobic or hydrophilic? What compositions of beeswax make it so?

Bonus:
What are pheromones? In what ways do bees use pheromones in their lives?

Isoamyl acetate (below) is the the main compound in bees’ alarm pheromone. Is this hydrophobic or hydrophilic? Draw out its full molecular structure.
Isoamyl acetate

Class Prep for Feb. 22: biological macromolecules

For Monday, please finish read the biological macromolecules section of your textbook—chapter 3 in OpenStax and Raven, section 3 of chapter 2 in EO Wilson’s  Life on Earth. Please note that EO Wilson’s Life on Earth has considerably less detail on this topic, so make sure that you’re able to get a handle on the key terms (which will be posted soon) through another resource if needed. Once again, there may be a reading quiz.