Biochem module 4 exam questions and answers already graded A

Biochem module 4 exam questions and answers already graded A Which of the following monosaccharides is a ketose? Dihydroxyacetone Galactose Glucose Glyceraldehyde Idose dihydroxyacetone When two carbohydrates are epimers: One is a pyranose, the other a furanose One is an aldose, the other a ketose They differ in length by one carbon They differ only in the configuration about one carbon atom They react differently with iodine They differ only in the confirmation about one carbon atom D.) alpha-D-glucose and beta-D-glucose Lactose is made from linking galactose and glucose. When this happens, _____. Gas is eliminated An anomeric carbon is formed on carbon-1 Water is released An epimer is formed An aldose is formed water is released Amylose and amylopectin are both polymers of: A) α-D-glucose B) β-D-glucose C) Galactose D) Idose E) Maltose A.) alpha-D-glucose Which statement about starch and glycogen is false? A) Both have β-D-glucose monomers B) Both starch and glycogen are energy storage polysaccharides C) Both are homopolymers of glucose D) Glycogen is more extensively branched than starch E) Both have O-glycosidic linkages A.) both have beta-D-Glucose monomers Which monosaccharide is not a six-carbon monosaccharide? Fructose Ribose Mannose Galactose Glucose ribose The two monosaccharides shown below could best be described as: Anomers Aldoses Ketoses Epimers Pentoses epimers Which arrow correctly identifies the atom that will become the anomeric carbon? The first carbon at the top of the Fischer structure Based on the form of the cyclic sugar below in a Haworth projection, which Fischer projection formula could have formed this structure? look at the hawthorn projection and create Fischer projections for it The following monosaccharides are covalently bonded. What type of bond unites them? alpha 1-6 vertical and through the downward pointing OH group off of carbon 1 1-4 is just side by side Which statement about cellulose is true? Cellulose is the primary storage polysaccharide of animal cells Cellulose is a highly branched polysaccharide Cellulose is a homopolysaccharide The glucose residues of cellulose contain the same configuration as the glucose residues of amylose Cellulose is an anomer of chitin cellulose is a homopolysaccharide The polysaccharide cellulose is most chemically similar to: Glycogen Dextrose Glycogen Chitin Starch chitin Which of the following is the most common monosaccharide on earth? Ribose Cellulose Chitin Sucrose Glucose glucose The "D" in the D-carbohydrates stands for: Derivation Double Disaccharide 3-dimensional Dextrorotatory dextrorotatory Which compound does not fit the formal definition of a carbohydrate? A. C6H12O6 B. C7H10O7 C. C8H16O8 D. C3H6O3 E. C4H8O4 B. C7H10O7 identify the hemiacetal bond includes the anomeric carbon, H, OH, and O in the ring tell the difference between alpha beta and D and L configurations D & L: look at the penultimate carbon L=left D=right alpha and beta. Alpha is the OH on the top of the anomeric carbon Beta is under the anomeric carbon Table sugar is also known as: Sucrose Dextrose Glucose Galactose Glycogen sucrose Amylopectin has α1 → 6 branching about every________ residues. 1 to 10 8 to 12 10 to 30 24 to 30 No branching 24 to 30 What element besides C, H, and O is found in the chitin? Br N P S Cl N Some carbohydrates form a(n)___________ structure, which resembles a structure in proteins. A) α form B) β-turn C) βeta-sheet D) D-configuration E) α-helix E.) alpha- helix The equilibrium between _________ structures is called mutarotation. A) Anomer and epimer B) α and β C) L and D D) Helix and beta sheet E) None of the above B.) alpha and beta Consider the functions of carbohydrates. Which of the following is not a function of these molecules? Structure Energy storage Enzyme structure Both A and B Both A and C enzyme structure The word saccharide means ___________. Sugar Carbohydrate Energy molecule Sucrose Starch sugar Table sugar dissolves easily in water. Given its structure, explain why this is. Surcrose contains -OH groups which can form hydrogen bonds with H2O. these non-covalent interactions allow solubility by permitting carbs to interact with H2O and become an aqueous solution. A) In the above structure, how many monosaccharide units are furanoses and how many are pyranoses? B) What is the linkage between the monosaccharides? C) Is this a reducing sugar? a.) 2 pyranoses and 0 furanoses b.) beta 1 to 4 c.) yes because it has a free anomeric carbon A hiker is lost in the wilderness and without food. He runs across several beetles with hard chitin exoskeletons. Would he get nutrition in the form of glucose from eating these beetles? Explain. Chitin is made out glucose residues with the beta 1 to 4 bond however human enzymes cannot break down this specific glucose residue because they can only act upon the alpha 1 to 4. so the hiker will not intake any glucose from eating the beetles and he should not eat the beetles. What is the difference between amylose and amylopectin? amylose is a single chain of glucose molecules connected by alpha 1 to 4 linkages. However, amylopectin also contains a main chain connect by alpha 1 to 4b linkages but it branches every 24 to 30 glucose residues. the branches are a different type of linkage called alpha 1 to 6 linkages however within the branched they contain alpha 1 to 4 linkages. A) Which carbon in the following molecule determines if the molecule is D or L? Indicate the letter corresponding the correct carbon ("A", "B", etc.) and explain. B) Is this molecule D or L? the penultimate carbon is the carbon that determines whether the molecule is D or L. In this scenario, the monosaccharide is D.