Chapter 3 The Molecules of Life

Chapter 3: The Molecules of Life Guided Reading Activities Chapter Content: Organic Compounds Complete the following questions as you read the third chapter content—Organic Compounds: 1. The element carbon is essential to an organic compound. 2. Is this molecule an organic compound? Briefly explain your answer. H H H C C H H OH Yes, since there are carbon and hydrogen elements within the molecule. 3. The oxygen atom in ethyl alcohol (the molecule pictured above) forms a polar covalent bond with the hydrogen atom. This causes the hydroxyl functional group (—OH) to have polarity (it is polar). Based on this, would you expect ethyl alcohol to readily interact with water? Briefly explain your answer. Hint—Think back to the end of chapter two. A functional group is a hydroxyl group. Ethanol interacts with water because the hydroxyl group imparts polarity to the ethanol, which permits it to be attracted to water. 4. Complete the following diagram using the following terms: dehydration reaction and hydrolysis. A) Hydrolysis Polymers B) Dehydration synthesis Monomers 5. Teachers commonly use a train and its numerous cars (engine, tanker cars, caboose, and so on) as an analogy to help students understand the relationship between monomers and polymers. Briefly explain why that is a good analogy. Since the train cars are attached in order to each other, as well as having single train cars, representing monomers, that are attached to each other making a larger train, this being a polymer, it is a good analogy. What functional group(s) can you identify in Figure 3.4 on page 39 of your textbook? 6. H2 O H OH H Short polymer OH H Monomer Dehydration reaction forms a new bond OH Hydrolysis breaks a bond H2 O OH H OH H H OH Longer polymer (a) (b) Both figures have hydroxyl groups, OH-. 7. Which of the following terms best describes the following reaction: glucose + galactose → lactose + H2O? A) Polymer B) Hydrolysis C) Metabolism D) Dehydration reaction 8. How are dehydration synthesis and hydrolysis opposites of each other? Be sure that your answer includes the mention of H2 O. In hydrolysis two molecules are split because of the separation of H2O. In the other hand, in dehydration the two molecules unite by removing the H2O. Chapter Content: Large Biological Molecules Complete the following questions as you read the third chapter content—Large Biological Molecules: 1. Complete the table that describes the four classes of large biological molecules. Carbohydrates Monomers Proteins Lipids Nucleic acids Amino acids Sugars Nucleotide Amino acids Not polymers Nucleotides Stores energy Storage and expression of genetic information. Monosaccharides Polymers Starch Provide energy, store Helps repair and build Major energy. body tissues, etc. function(s) Build macromolecules. Spare protein, and fat. 2. Which of the following is a characteristic of carbohydrates? A) Energy source for animals B) Consists of sugars and sugar polymers C) A structural component in plants D) All of the above are characteristic of carbohydrates c c 3. The monomers of carbohydrates are monosaccharides 4. Sweetened beverages from coffee to tea to soda are a regular part of almost everyone’s daily routine. Briefly explain why sugars, like sucrose, readily dissolve in water. Hint—Consider the role of the hydroxyl group (—OH). The sugars in this beverages dissolve in water because they have hydroxyl groups. 5. Complete the following table regarding monosaccharides and polysaccharides. Starch Identify as a monomer or polymer Describe the function 6. Glucose polymer monomer Cellulose Glycogen polymer polymer A way to store energy Provides energy to most for plants. It is also a cells in our body. It can source of sugar in an also be found as a form of animal’s diet. storage molecules. Connects cells to form It’s a sources and tissues that have control reserve of of the shape of the plant cells. Refer to Figure 3.8 on page 41 of your textbook to answer the following question. What new item will be added to nutrition labels beginning in 2018? Briefly explain why this is being required on nutrition labels? The new item added to the nutrition labels beginning in 2018 was added sugars. It is recommended to limit added sugars as it makes it difficult to meet nutrient needs while staying within the calorie limits. Nutrition Facts 8 servings per container Serving size 2/3 cup (55g) Amount per serving Calories 230 % Daily Value* Total Fat 8g Saturated Fat 1g 10% 5% Trans Fat 0g Sugars added during manufac Cholesterol 0mg 0% Sodium 160mg 7% Total Carbohydrate 37g Dietary Fiber 4g 13% 14% Total Sugars 12g Includes 10g Added Sugars 20% Protein 3g Vitamin A 8mg 10% Vitamin C 5mg 8% Calcium 260mg 20% Iron 8mg 45% *The % Daily Value (DV) tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice. n 10% of total daily calories. 7. The one characteristic common to all lipids is that they are hydrophonic contrast to most other biological molecules. 8. The following diagrams are simplistic illustrations of lipids like you might see in Figure 3.11 from page 43 of your textbook. Which fatty acid tail(s) from the illustration is/are saturated? Which one(s) is/are unsaturated? Briefly explain your answers. When answering the question, think of the tails in each lipid as being numbered 1, 2, and 3 from left to right. 1 9. 2 3 saturated 1 2 3 , which is in Unsaturated You are a biochemist working for a food manufacturer. You are working to identify a new fat you have discovered in a tree from the rainforest of Indonesia. During your examination, you determine that the fat tends to be a liquid at room temperature, and a biochemical analysis reveals too few hydrogen atoms for carbon that is present. What kind of fat have you likely discovered? Briefly explain your answer. The fat that has been likely discovered is an unsaturated fat. This is known due to few hydrogen atoms found as well as the compound’s liquid nature, which demonstrates the existence of carboncarbon double bonds. 10. An unsaturated fat can be turned into a solid or semisolid state by . A) Omega-3 fatty acidification B) Hydrophilication C) Hydrogenation D) Unsaturation 11. Cholesterol is used within the cell’s membrane and as a precursor to other steroids synthesized by cells. 12. Which source has the highest percentage of saturated fats? Use Figure 3.12 on page 44 of your textbook. 13% saturated 50% 37% poly- unsaturated mono- unsaturated Corn oil 9% polyunsaturated 41% 50% mono- unsaturated saturated 3% polyunsaturated 39% mono- unsaturated Palm oil 58% saturated Butter Butter. 13. are the monomers from which large proteins are constructed. A) Polymers B) Amino acids C) Polypeptides D) Peptide bonds 14. Regardless of its specific function, a protein’s function is absolutely dependent upon its Amino acids . 15. True or false: Amino acids are joined together through a dehydration synthesis reaction forming a peptide bond. 16. Proteins serve many functions within your body. List three functions served by proteins in your body. Structure, function, and regulation. 17. A polypeptide is 107 amino acids in length. 106 water molecules were removed during synthesis of the protein. What kind of bond is all of the dashes connecting the amino acids in Figure 3.20a representing? Thr Pro Glu Glu Lys Ser Ala Val Thr Ala Leu Trp Gly Lys Val Asn Val Asp Val His Leu 20 5 10 15 Glu 1 Phe Arg Gln Thr Trp Pro Tyr Val Val Leu Leu Arg Gly Phe 40 Glu 45 50 Ser Phe Gly Asp Leu Ser Thr Pro Asp Ala 35 Ala Thr Leu Ser Glu Leu Pro His 75 Cys Asp Lys Gly Phe His 120 Gln Ala Ala Tyr 25 55 Val Met Gly Asn Pro Gln Lys 130 His Val 60 Lys Ala His Val Asp Pro Glu Asn Phe Arg Ala Leu Val Cys Val Ala Gly Val Val Leu Leu Val Asn Gly Tyr His 110 Ala Asn Ala Leu Ala His 135 Gly 65 Phe Leu 105 100 His 115 Val Lys 70 Lys Leu 95 Thr Phe Glu Val Ala Leu Gly Asp Ser Phe Ala Gly Leu 90 125 Pro Val Gly 30 Gly Lys Leu Asn Asp Leu His ThrVal Lys 80 Lys 85 Leu Ala Glu Gly SEM 500* 18. Lys 140 Amino acid sequence of normal hemoglobin 145 Normal hemoglobin polypeptide Normal red blood cell Peptide bonds. 19. A(n) gene is considered to be the unit of inheritance, which is actually made of the . nucleic acid polymer known as n u c l e o t i d e s 20. List the three molecular components that all nucleotides have: A) Nitrogenous base B) phosphate group C) 5-carbon sugar 21. You are analyzing a sample of a nucleic acid and determine that the sample contains the nitrogenous base adenine. Are you able to determine if the sample is DNA or RNA? Briefly explain your answer. No, it can’t be determined because adenine can be found in RNA and DNA 22. What would be the complementary sequence to the following strand of DNA? AGGCGATATAC TCCGCTAT ATG 23. The famous structure of a molecule of DNA is the . A) Triple helix B) A shapeless blob C) Pattern seen in a chain link fence D) Double helix 24. Complete the following table that illustrates the differences between DNA and RNA. DNA Difference 1 Double stranded Double helix Difference 2 Difference 3 Dexoriibose RNA Single stranded Single healix ribose Major Theme Connection: 1. Why was it beneficial for Northern Europeans to be lactose tolerant when lactose intolerance was more common in most other places? It was beneficial due to their dependence on animals to get them through rough winters and short growing seasons. Common Thread Connection: 1. You go out to dinner with your best friend. During dinner you consume the following meal: spinach greens with sunflower seeds, a Dr. Pepper™, and a piece of buttered French bread. Identify the biological molecules that would likely be present and what they would be processed/digested into after they are consumed. There is very little within the way of calories in the spinach as it is mostly cellulose. The sunflower seeds will have proteins that can be digested into amino acids and the seeds will have fats. To add on, The Dr. Pepper will contain simple sugars, while the French bread will contain starch that can be broken into glucose molecules and the butter will contain saturated fats.