Macromolecules Practice Assessment PDF

LS15 Peer Learning | Week 6 Session 2 [email protected] Macromolecules Practice Assessment 1. The ingredient label on a container of shortening indicates “partially hydrogenated vegetable oil.” This...

LS15 Peer Learning | Week 6 Session 2 [email protected] 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? a) The oil now has a lower melting point. 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 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 foods that is high in fat Stores the most energy of all macromolecules (9 kcal vs Kcal) In EEA (environment of evolutionary adaptiveness) hunter-gatherer society- we ahad to make sure that we had enough energy to survive even when food sources were unpreductable so we were motivated to eat foods that had more fat Have a taste preference for lipids because it stores energy and heat insulation which was important for our ancestors who struggled to find food. Macromolecules Fuel comes from energy stored in Chemical bonds (forces that hold atoms together to form molecules or compounds) - Bonds store in potential energy LS15 Peer Learning | Week 6 Session 2 [email protected] Chemical reaction (how energy is released) : bonds in molecules are broken down and new molecules are created. - These new bonds store less energy. - The energy released is used as fuel for an organism. What are macromolecules? Large organic (contains 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 molecule; relatively simple sets of building blacks linked together by covalent bonds Building blocks of polymers Covalent Bonds- chemical bond that form when two atoms share electron Ionic Bonds - One atom transfers one or more electrons to another atom Metallic Bonds: occur between metal atoms where electrons are shared freely in a sea of electrons that moce around all the metal atoms 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 - Not water soluble (can't dissolve in water) Hydrocarbon chain: chain of connected carbon atoms with hydro atoms, they are main components of organic molecules, fats,oils, and fuel. Types of fats: refers to the hydrocarbon chain of the fatty acids Saturated fat: 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 Example: Butter, cheese, meat (animal fats) LS15 Peer Learning | Week 6 Session 2 [email protected] (Have double bonds that create kinked tail) Unsaturated fat: 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 temp Examples: Vegi oil, fish,walnuts, plants Structure of fats Saturated Unsaturated 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 (fats)? - Contains more than twice as much stored energy in other macromolecules (9kcal vs 4) - Humans have evolved to want to store energy (ancestors are hunter gatherers. Haven't adapted to the current environment) What is partially-hydrogenated vegetable oil and why do we use it? - Take oil and bubble up the hydrogen (hydrogen atoms will attach to fat structure at some places) - Double bonds will become single bonds and put hydrogen back in so it is less reactive and solid at room temp - Why: Longer shelf life (keep them in the warehouse longer) and control desired texture/melting point (ex: chocolate) Partially-hydrogenated vegetable oil is a type of oil that has undergone a chemical process called partial hydrogenation to make it more solid or stable at room temperature. This process involves adding hydrogen atoms to LS15 Peer Learning | Week 6 Session 2 [email protected] unsaturated fats, which reduces the number of double bonds in the oil and can transform it from a liquid to a more semi-solid form. Carbohydrates Function: Primary fuel source (provide energy for the body)? Form structure of cells - brain is using to think and do stuff - Shorter, more oxygen, can break faster Types of carbohydrates Simplest sugars monosaccharides ○ 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) A complex carbohydrate, indigestible by humans, that serves as the structural material for a huge variety of plant structures. It is the single most prevalent organic compound on earth. 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) Plant carb (fiber) helps move food through the digestive system -> shows why it is important for humans __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) LS15 Peer Learning | Week 6 Session 2 [email protected] Structure of carbohydrates Starch Cellulose