6.2 - Macromolecules (Solutions) PDF

LS15 Peer Learning \| Week 6 Session 2 marolah135712\@g.ucla.edu [Macromolecules Practice Assessment] 1\. The ingredient label on a container of shortening indicates "partially hydrogenated vegetable oil." This means that during processing the number of carbon-carbon double bonds in the oil was re...

LS15 Peer Learning \| Week 6 Session 2 marolah135712\@g.ucla.edu [Macromolecules Practice Assessment] 1\. The ingredient label on a container of shortening indicates "partially hydrogenated vegetable oil." This means that during processing the number of carbon-carbon double bonds in the oil was reduced. What is the result of decreasing the number of double bonds? Solid -\> liquid a\) The oil now has a lower melting point. (need more heat to break down) b\) There are more "kinks" in the fatty acid chains, reducing the membrane density. c\) The oil now contains a higher percentage of carbohydrate. d\) The fatty acid is modified from a diglyceride into a triglyceride. e\) The oil is now more likely to be solid at room temperature. 2\. Non-digestible plant fiber, such as cellulose, is a type of: a\) protein. b\) carbohydrate. c\) fatty acid. d\) nucleic acid. e\) amino acid. 3\. What of the following is NOT a characteristic of a saturated fat? a\) Have straight Carbon Hydrogen backbones b\) Tend to be liquid at room temperature c\) Can be packed together tightly d\) Carry the maximum number of Hydrogens per Carbon e\) None of the above 4\. When it comes to food, humans have taste preferences. What are they and why do they exist? Prefer food that is high in fat Stores the most energy of all macromolecules (9 kcal vs. 4 kcal) In EEA (environment of evolutionary adaptiveness)/hunter-gatherer society - we had to make sure that we had enough energy to survive even when food sources were unpredictable so we were motivated to eat foods that had more fat - Fuel comes from energy stored in \_\_\_\_\_chemical bonds\_\_\_\_\_. *Bonds in molecules are broken down and new molecules are created. These new bonds store less energy. The energy released is used as fuel.* What are macromolecules? *Large organic (contain carbon/found in living systems) molecules made up of smaller building blocks Molecules that are necessary for life/provide energy/structure.* *4 types: Lipids, carbohydrates, proteins, nucleic acids* Monomers: *subunits; molecules that can be bonded with other molecules; Relatively simple sets of building blocks linked together by covalent bonds* Polymers: *structure with repetitions of similar units; possible to form an almost infinite variety of complex molecules, called polymers* **Lipids** (A.K.A. \_\_fats\_\_\_\_ ) Function: *Storehouse for energy/dense source of energy that can be efficiently stored in the body Also good insulator/keeps body warm* - Types of fats **\_\_\_*[Saturated]*** [*Fats\_\_\_\_*\_]\_ : *○ **Single** bonds (Carbons connected with 2 Hydrogens)* *○ **Straight** tails/can be packed tightly together* *○ More likely to be **stored** as fat rather than used for energy* ○ ***Solid** at room temperature* Examples: *Butter, cheese, meat (animal fats)* \_\_[*\_\_Unsaturated Fats\_\_*\_] : *○ Kinked tails (double bonds that connect carbon - fewer hydrogen molecules)* *○ Cannot be packed together tightly* *○ Less likely to be stored as fat/easier to break down (enzymes have better access)* *○ Tend to be liquid at room temperature* Examples: *Vegetable oil, fish, walnuts (plant/fish fats)* Structure of fats Saturated Unsaturated ----------------------- Structure of fats (extended) -- -- Which type is better for your health? Why? *Unsaturated fats are better because they are more reactive and can get more nutrients* Why do humans love food with more lipids? * Contains more than twice as much stored energy as other macromolecules (9kcal vs 4)* * Humans have evolved to want to store energy (ancestors are hunter-gatherers. Haven't adapted to current envr)* What is \_\_\_[*partially-hydrogenated*\_]\_\_ vegetable oil and why do we use it? -\> illegal in US now * Take oil and bubble up hydrogen (hydrogen atoms will attach to fat structure at some places) Double bonds will become single bonds and put hydrogens back in so it is less reactive and solid at room temperature* * Why: Longer shelf life (keep them in the warehouse longer) & control desired texture/melting point (ex. chocolate)* LS15 Peer Learning \| Week 6 Session 2 marolah135712\@g.ucla.edu **Carbohydrates** Function: *Primary fuel source (Provide energy for the body)/Form structure of cells - brain is using to think and do stuff* - Types of carbohydrates [*\_\_Simple Sugars/Monosaccharide\_\_*\_]\_ : *○ Linear/ring structure with 3-7 carbon atoms* *○ Fast/immediate energy* Examples: *Glucose (plants), fructose (fruit, veggies)* \_\_\_\_[*Complex Carbohydrate/Polysaccharides\_*\_]\_\_ : *○ Simple sugars linked together (with glycosidic linkages)* *○ Energy breaks down more slowly (or not at all)* Examples: *Glycogen, starch (energy storage in plants), cellulose/lignins/pectins/gums (fiber in our diet)* What is cellulose? * Used for structural support in plants (is fiber: adds bulk -\> helps move food through digestive system)* - How is cellulose different from other carbohydrates (starch)? * Humans and mammals can't digest because we can't break down bonds (beta amylase only found in plants, bacteria, and fungi)* - \_\_[*alpha\_*\_] linkage: *connects starch (same bond repeats - enzyme alpha amylase breaks down)* \_[*\_beta\_\_*\_] linkage: *connects cellulose (direction alternates) - enzyme beta amylase breaks down. Not in humans)* Structure of carbohydrates Cellulose Stratch ----------------------- ---------