Chemistry Student Edition: Answers on Biochemistry, Amino Acids, Lipids, and Nucleic Acids, Summaries of Biochemistry

Download Chemistry Student Edition: Answers on Biochemistry, Amino Acids, Lipids, and Nucleic Acids and more Summaries Biochemistry in PDF only on Docsity! Chemistry Student Edition - Basic Answer Key Chapter 26: Biochemistry Carbohydrates Questions 1. What is the origin of the term “carbohydrate”? 2. Name the term used for carbohydrates with the following chain lengths: a. four carbons b. six carbons c. five carbons 3. Classify each of the following carbohydrates as a monosaccharide, a disaccharide, or a polysaccharide: a. lactose b. ribose c. glycogen d. galactose e. sucrose f. starch 4. How many pyruvate molecules can be formed from the metabolism of three molecules of glucose? 5. What relationship is there between glucose metabolism and ATP formation? 6. Explain how glycogen and amino acids (components of proteins) can both be used to produce glucose in the bloodstream. Answers 1. Carbohydrates have the general structure Cn (H2O)n, where n is some integer. 2. a. Tetrose b. Hexose c. Pentose 3. a. Disaccharide b. Monosaccharide c. Polysaccharide d. Monosaccharide e. Disaccharide f. Polysaccharide 4. Six 5. Pyruvate can be converted to acetyl CoA which then goes through a complex series of reactions leading to the utilization of oxygen and the formation of ATP. 6. Glycogen is a storage form of glucose. When the body needs more glucose, the liver is signaled to breakdown glycogen into simple glucose units to be released into the blood. Amino acids (from proteins) lose an amino functional group to become starting materials for gluconeogenesis. [Review Ch. 25] Amino Acids and Proteins Questions 1. Draw a generic amino acid. 2. Draw a structure showing how two amino acids form a peptide bond. 3. Define the following aspects of protein structure: a. primary b. secondary c. tertiary d. quaternary 4. List six common functions of proteins. 5. Write the generic form for an enzyme-catalyzed reaction. 6. Describe the structure of the hemoglobin molecule. 7. Describe the molecular defect that causes sickle-cell disease. Answers 1. 2. 3. a. primary – amino acid sequence b. secondary – local folding (alpha helix and beta pleated sheet) c. tertiary – three-dimensional structure d. quaternary – subunit composition if more than one protein chain present 4. a. antibodies b. transport c. structural d. enzymes e. storage f. hormones 5. enzyme + substrate → enzyme-substrate complex → enzyme + product 6. The hemoglobin molecule has four subunits (two alpha chains and two beta chains). Each chain contains a porphyrin ring with iron in the center. 7. Sickle-cell disease is the result of one specific mutation within the primary sequence of the hemoglobin molecule. When oxygen is released from the hemoglobin to enter the cell, the protein conformation changes. These abnormal amino acids interact with other hemoglobin molecules to form protein aggregates that cause cell sickling and damage. Lipids