Lesson 2 GRQs Structure Function of Macromolecules PDF

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This is the GRQ for lesson 2...

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Guided Reading Qs: Do these before the Mastering Assignment.

Structure/Function of Macromolecules (Read sections 2.6-2.10 and all of chapter 3) Reading Objectives:  Describe differences in molecular bonds that hold organic molecules together.  Explain the structure and function (and categorize) the monomers and polymers of carbohydrates, lipids, proteins, and nucleic acids.  Compare observational vs. experimental studies and retrospective vs. prospective studies  Explain the evolution of lactose tolerance ( Op t i o na l :I fy ouha v eno tt a k e nab a s i cc he mi s t r yc l a s sr e c e nt l y , Ie nc our ag ey o ut os k i m s e c t i o ns2 . 1 2. 5a ndt a k eno t e s ) Section 2.6-2.10 1. List the molecular bond types a. Covalent Bonds - share electrons (1, 2, or 3 pairs); can be VERY strong. Two Types: 1. Nonpolar Covalent Bonds - electrons shared equally Example? Carbon and Hydrogen 2. Polar Covalent Bonds - electrons are not shared equally creating “poles” a slightly negative and slightly positive end Example? Oxygen and H2O

b. Ionic Bonds - electrons are not shared Example molecule using these bonds? Sodium Chloride

c. Hydrogen Bonds - attraction between a slightly positive hydrogen (from a polar molecule) and a slightly negative atom (from a different polar molecule) Properties of this kind of bond? Example? Weak, high melting point, high boiling point

2. In photosynthesis, CO2 and H2O are the reactants. What are the products? Has matter been created or destroyed? Glucose and oxygen; it cannot be created or destroyed, only rearranged

Chapter 3 (Focus on the questions here—DO NOT highlight and outline the entire chapter) 1. What is an organic compound? Which one of these is an organic compound? Water Carbon dioxide Glucose 2. What does the word hydrophilic mean? Water-loving; soluble in water 3. Think about making a necklace with small beads. Use the necklace as an analogy to use the words macromolecule, monomer, polymer, dehydration reaction, and hydrolysis in sentences. Each bead represents a monomer, the whole necklace is a macromolecule and a polymer of the beads. The process of making the necklace is a dehydration reaction. If you break the necklace, it will be hydrolysis. 4. Dr. Hogan (of European descent) is lactose intolerant and must pop a few pills before eating her favorite chocolate ice cream. What is she missing? What is in those pills? The enzyme lactase Look back at the chapter 3 opening essay, Americans of what descent are most likely to be lactose intolerant? Asian Americans 5. The monomers of carbohydrates are: monosaccharides. Name a few from the reading: Glucose & Fructose The use of sugars as both energy resources and organic building blocks clearly illustrates one of our five themes of life: Energy & Matter.

6. Describe how two monosaccharides are joined and what forms when they are chemically joined: Two monosaccharides join by dehydration reaction; disaccharides form when they are chemically joined. 7. How much sugar does the typical American consume daily? 22 teaspoons Yearly? 26 bags (more than 5 pounds)

What correlation has the NHANES study made with increased sugar consumption? Participants who consumed more than 25% of their daily calories from added sugars were almost three times as likely to die as a result of cardiovascular diseases than those who consumed less than 10% 8. List and describe each of the four polysaccharides discussed in 3.7: 1. Starch: long chains of glucose monomers; stores polysaccharides in plants; branched or unbranched; potatoes and grains are the major sources of starch in the human diet 2. Glycogen: animals store glucose in this polysaccharide; more highly branches than starches; most glycogen is stored as granules in your liver and muscle cells, and release glucose when needed 3. Cellulose: the most abundant organic compound on Earth; major component of tough walls that enclose plant cells; cellulose molecules joined by hydrogen bonds; NOT a nutrient for humans; structural 4. Chitin: used by insects and crustaceans to build their exoskeleton; also found in cell walls of fungi; structural Next to each, describe if it is from a plant or animal. Does it function as a “storage” or a “structural” polysaccharide? 9. Most carbohydrates and biological molecules are hydrophilic. What chemical property is shared by lipids? Hydrophobic (don’t mix well with water) 10. What are the monomers of a triglyceride (fat) molecule? Glycerol & fatty acids Make simple drawings (cartoon like, not chemical) of a saturated triglyceride vs. unsaturated triglyceride:

Compare and contrast unsaturated and saturated fats in terms of structure and where they can be found. Unsaturated fats – a fatty acid whose hydrocarbon chain contains one or more double bonds Ex. Fats of plants and fishes Saturated fats – a fatty acid that has no double bonds but its hydrocarbon chain has the maximum number of hydrogen atoms attached to each carbon atom (its carbons are “saturated” with hydrogen) Ex. Animal fat 11. What is the main function of fats? Fats are used as a fuel source Why do plants use starch for energy storage whereas animals use fats? Plants use starch because it is not as bulky as fats are, since plants are immobile 12. Module 3.9 is a Scientific Thinking Module in which you get to read about real studies and the data produced from them. What was the hypothesis of the experimental study described? What are the limitations of this kind of experimental study in humans? Trans fats adversely affect cardiovascular health. They predicted that the more trans-fat in the diet, the greater the risk. The limitations are that you cannot make a human do this experiment because it could lead to them having heart attacks. What is the limitation of retrospective observational studies with humans and diet? People may not correctly remember and report their dietary histories, and anyone who has already died, say, of a heart attack, would not be included in the study. Was the Nurse’s Health Study experimental or observational? Observational Retrospective or prospective? Prospective What were the results and conclusion? Trans fats are indeed a greater health risk than saturated fats. How did the results affect policy in the U.S.? The US government has revised policies and banned saturated fats, which should’ve been taken out of foods by the year 2018

13. Draw and label a picture of a phospholipid (cartoon form, not the chemical structures): Be sure to use these labels: head, tail, hydrophobic, hydrophillic

14. Fats, phospholipids, and steroids are three main types of lipids. 15. What do anabolic steroids mimic in the body and what effects do they have? Testosterone; may cause violent mood swings, depression, liver damage, cancer, high cholesterol or blood pressure, reduce output of male sex hormones, breast enlargement 16. What are the monomers of proteins? Monomers – amino acids 17. A proteins’ function depends on its shape. When a protein “unravels” or unfolds we call this denaturation. It no longer functions. When proteins fold incorrectly they can cause disease. Which diseases? Alzheimer’s and Parkinson’s 18. There are 20 different amino acids, what part of each amino acid makes it different from the other amino acids? The chemical properties of their R groups / side groups 19. Protein structure A. 1o structure -amino acids (monomers) joined together through a dehydration reaction. The bonds between amino acids are peptide bonds, what kind of bond or linkage are these? Peptide bonds B. 2o structure– held together by weak hydrogen bonds between the amino group of one amino acid and the carboxyl group of another amino acid C. Describe the next two levels of protein structure: Tertiary structure – stabilized by interactions between R-groups Quaternary structure – four identical polypeptides are associated into a functional protein 20. What are the monomers of DNA? Nucleotides

The DNA sugar-phosphate backbone is held together by covalent bonds. What kinds of bonds hold the two strands of the double helix together? Hydrogen bonds 21. Lactose tolerance is a mutation that has arisen many times in human evolution. In which populations has this been naturally selected for as a useful adaptation? Why, what is the selective pressure in these cultures? North European descent because it offered a survival advantage; selective pressure – cold winters and drought 22. Explain how lactose tolerance involves three of the four major classes of biological macromolecules. Lactose, milk sugar, is a carbohydrate that is hydrolyzed by the enzyme lactase, a protein. The ability to make this enzyme and the regulation of when it is made is coded for in DNA, a nucleic acid...