An astronaut of mass 210 kg including his suit and jet packwants to acquire a velocity of 2.0 m/s to move back towardhis space shuttle. Assuming the jet pack can eject gas with avelocity of 35 m/s, what mass of gas will need to be ejected?
Review for Chapter 16 Biochemically important sugars usually contain five or six carbon atoms; their structure includes a carbonyl group (either the aldehyde or the ketone form) and several hydroxyl groups. Optical isomerism is of paramount importance in the structure of simple sugars. Most of the important sugars found in nature have the D configuration, based on the standard compound D-glyceraldehyde. Most sugars exist in cyclic forms with five- or six-membered rings. The cyclization process involves the carbonyl group and gives rise to another chiral center in addition to the ones already present in the sugar molecule. The two possible cyclic isomers, called anomers, are designated α and β. 1. Define the following terms: Polysaccharide: formed when multiple monosaccharides are bonded together. Oligosaccaride: formed when a few monosaccharides are linked. Monosaccharide: A carbohydrate that can't be hydrolized to a simpler carbohydrate o Building blocks of all carbohydrates o they have the general formula C (n)H(2n)O(n) or CHO where naries from 3 to 8 o simplest form are trioses o classified by the number of carbon atoms Aldose: a monosaccharide containing an aldehyde group Ketose: A monosaccharide containing a ketone group Epimer: compounds having the same chemical formula but differ in the spatial arrangement around a single carbon atom. 2. What is the difference between an enantiomer and a diasteromer Enantiomers are stereoisomers that are mirror images and Diasteromers are stereoisomers that are not mirror images (one of the carbon atoms constituants are changed 3. How many possible epimers of D-glucose exist there are 2 epimers of D-glucose D-mannose: differs from D-glucose ONLY at the 2nd Carbon atom. Hence it is a C-2 epimer of D-Glucose D-galactose: Differs from D-Glucose ONLY at the 4th Carbon atom. Hence, it is a C-4 epimer of D-Glucose. 4. How many chiral centers are there in the open-chain form of glucose In the cyclic form in the open chain form of glucose there are 4 chiral centers and in the cyclic form there are 5 5. Identify the pairs that are enantiomers and the pairs that are epimers. Enantiomers: (A&F); (B&D) mirror images of each other Epimers: (A&C) (C&E) and (A&E) differ in one of the Carbon atoms (A&E) the second carbons arms are switched A & C the 3rd carbon atom arsms is switchedmand so on A carbohydrate Fischer projection. 6. The carbohydrate shown is a. a monosaccharide b. a ketose. c. a hexose. d. all of these e. none of these 7. The carbohydrate shown is a. the D isomer. b. the L isomer. c. both D and L. d. neither D nor L. e. It's impossible to tell from a picture which isomer this is. 8. Epimers are a. stereoisomers that differ from each other in their configuration at two or more carbon atoms. b. stereoisomers that differ from each other in their configuration at a single carbon atom. c. the and forms of cyclic sugars. d. two related compounds, pyran and furan. 9. The simplest ketotriose is a. glyceraldehyde. b. dihydroxyacetone. c. ribose. d. glucose. e. sucrose. 10. In a Fischer projection, which chiral carbon determines whether the sugar is the D- or the L-isomer a. highest numbered carbon atom b. lowest numbered asymmetric carbon atom c. lowest numbered carbon atom d. highest numbered asymmetric carbon atom 11. Which of the following groups is produced when an aldehyde is oxidized a. ketone b. carboxyl c. alcohol d. ether 12. Which of the following compounds is produced by oxidation of an aldose in the cyclic form a. a hemiacetal b. a hemiketal c. a lactone d. an amino sugar 13. The conversion of a sugar's carbonyl to an alcohol is a. a reduction reaction. b. an oxidation reaction. c. a glycosidic reaction. d. impossible. 14. Which of the following groups is produced when an aldehyde is oxidized a. ketone b. carboxyl c. alcohol d. ether 15. Which of the following compounds is produced by oxidation of an aldose in the cyclic form a. a hemiacetal b. a hemiketal c. a lactone d. an amino sugar 16. The conversion of a sugar's carbonyl to an alcohol is a. a reduction reaction. b. an oxidation reaction. c. a glycosidic reaction. d. impossible. 17. Which of the following best describes the glycosidic bond in the disaccharide shown a. α(1-4) b. β(1-4) c. α(2-4) d. β(2-4) e. None of the above. 18. Glycosidic bonds from sugars a. always link to the other molecule through an oxygen atom. b. always link to the other molecule through a nitrogen atom. c. may link to the other molecule through either an oxygen or a nitrogen atom 19. Sucrose is composed of the following simple sugars: a. galactose only b. glucose only c. fructose only d. galactose and glucose e. glucose and fructose f. galactose and fructose 20. The difference between cellobiose and maltose is: a. one contains glucose and the other fructose b. they contain different monosaccharides c. they both contain glucose units but are connected together at different carbons d. one has an α linkage and the other a β linkage e. there is no difference between the two 21. Which of the following is not a reducing sugar a. glucose b. fructose c. sucrose d. maltose 22. Lactose intolerance a. arises from inability to metabolize the disaccharide lactose b. depends on a deficiency of sucrose in the diet c. is based on the composition of lactose, consisting glucose and fructose in glycosidic linkage d. arises because lactose is a dimer of galactose 23. Which of the following disaccharides cannot be digested by mammals a. cellobiose b. sucrose c. maltose d. lactose 24. In bacterial cell walls a. polysaccharides form nonspecific mixtures with proteins b. polysaccharides are hydrogen bonded together c. peptides form crosslinks between polysaccharides d. oligosaccharides form crosslinks between proteins 25. Which of the following molecules have the highest degree of a[1-6] branching linkages a. Amylose b. Amylopectin c. Starch d. Glycogen e. All of these have the same degree of branching 26. A major difference between amylose and amylopectin is that a. amylose is connected by a(1-4) bonds and amylopectin is connected by b(1-4) bonds. b. amylose is branched and amylopectin is not. c. amylopectin is branched and amylose is not. d. each is composed different types of sugar residues. 27. Amino or acid derivatives of sugars are very important in which of the following biological functions a. Structural roles b. Lubricating fluids c. Cell surface sugars used in cell identity d. Both structural roles and lubricating fluids. e. All of the above are functions of amino and acid sugar derivatives.