J. A. CAMPBELL Honey Mudd College Cloremont, California 9171 1
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Eoc-ohem is a column of ouestions (nlus nossible. but eertt~inlvnot uniouelv satisfaetorv. ~, . . answers). reouirine., no more rhan s rnncurrent ~ ~ T J I - Y P ~1.011~9e T, level WUILP, II d-111 handl,m,k, and n aillin~nw-iI l r apply ft.ndnrnrntnl rhemiwl ideas I,, the syutemr whirl, sorromd us (ur even are in-id? i l i . ('wtritmtims for por.iil,lr invlu-im are solicited. Initiated in the January, 1972 issue of THIS JOURNAL. ~
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Questions Q7. Blood group antigens can only come from parents, though some parental antigens may be missing in the offspring. Detection of these antigens may help solve paternity snits, interchanged-baby-cases in hospitals, and breeding record mixnps in other animals. Assign the two sets of non-identical twins (3,4,5,6) all born on the same day to the appropriate parental couples 1,:' and 2,2'. Repeat for the cattle problem. Al A2 B M N
P
D
+1 1+ ' +2 2 '+ 3 4 + + + + + ++ + ++ ++ ++ A
Cow Bull 1 Bull2 Calf
B
C
F
H
+5 6+ ++ + + + J
O
R
S
D, 250-1000. The corresponding values in bread are 60y0 of the above. Why require these additives to wheat flour rather than, for example, to milk? The addition of a small amount of lysine to flour would markedly increase the use of the protein in the flour, yet this addition is not allowed (though there would be no harmful physiological effects). Why? Q10. 100 ml of blood contains about 15 g of hemoglobin (HHb), holds about 20 ml of Oz when fully oxygenated, and has 98% of this value in arterial blood leaving the lungs and 75% in normal venous blood. At what minimum average rate must a heart beat pump blood in a person utilizing 3000 kcal of energy per day?
V
+ ++ + ++ ++ + + + ++ + + + + + ++ ++ + ++
Q8. The atomic composition of the entire known universe approximates 93 atomic percent H and 7 atomic percent He (with only traces of other elements). Calculate the weight percent of H and He. Q9. Enriched wheat flour is required by law in Canada, many Central American countries, and about half the United States where the FDA limits in mg/lb are: thiamine, 2.0-2.5; riboflavin, 1.2-1.5; niacin, 16.0-20.0; iron, 13.0-16.5; calcium, 500-625; vitamin
1 ml Oz generates about 5 cal. Blood volume is about 6 1 (range 4-7.8). Q11. About 2 lh of yeast (a single-celled microorganism) are grown annually per person in Europe and N. America. Production of 1 lb of dry yeast solids (45% protein) requires (in pounds) as nutrients approximately 4.3 molasses (contains some H20),0.9 NH3, 0.3 NHAH9P04. If the "em~iri. - ., 1.1 (NHMOd, -,-,and 60 air. cal chemical formula" of yeast a .~-~ r o x i m a tCllaHlslOas es N18P2S,which reactant is probably in greatest excess? ~
Answers A7. Twins 3 and 6 come from parents 2, 2'. Twins 4 and 5 from 1 and 1'. Note that antigens B, M, and D provide no selective information. The calf came from bull 2 as proved by antigens R, W, a n d Y ~ . A8. In 100 moles there will be93 H and 7 He. The weights = 93 H, 4'0 = 28gHe2 93 + 28 = be: 93 g' loo 931121 = 77 wt% "' loo 28/121 = 23 wtO/, He. A9, Bread is preferable to milk as a food enrichment route since higher fraction of peopleof all ages (except very eat bread than drink milk. ~h~ only reasonable interpretation of the lysine situation must be east effectiveness. Presurnahly there is enough protein in U.S. diets that there is little reason the population should pay extra for adding lysine to flour. The cost effectivenessmight be quite different with a differentdiet.
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Journol o f Chemical Education
A10. You need a heartbeat rate to solve the problem so count your own. I t will prohahly be about 70 beatslmin. Oz) = 6 x 105 ml O2re3000 kcal x 1000 (cal/k~~I)/5(cal/ml quired per day per person. 6 X lo6 (ml 02/day)/[24(hr/day) 60 70 (beats/min)l = 6 ml on/heilrtheat must be pumped an average assuming constant rate over 24 hr. Now 100 ml of arterial blood contains ahout 20 ml Oz hut only about 25% of this is used (venous blood still holds 75% of the oxygen). So the effective holding capacity of blood is about 5 m l 0 per ~ 100 ml. Thus, the heart must pump about 100 ml of blood Per beat. Actually, each heat is double in that half the heart Pumps 100 ml of blood Per beat to the lungs while the other sends 100 ml to the rest of the body. In this sense a moderately working heart pumps about 200 ml per best. At rest it pumps about 2 X 50 ml/beat.
All. C,,4H,810,&8P~Shas a formula weight of 2755. One pound contains C 114 X 12.0/2755 = 0.4951b H 181 X 1.01/2755 = 0.0660 ih 0 45 X 16.012755 = 0.261 lb N 28 X 14.0/2755 = 0.142 lb P 2 X 31.012755 = 0.027 1b S 1 X 32.1/2755 = 0.0117 lb Neglect H and 0 which are abundant in the reagenb and in the aqueous nutrient solution. 4.3 lb molasses [assume (CH2O)J contains (12/30) X 4.3 = 1.7 lb C.
0.9 lb NHs wntains (14117) X 0.9 = 0.7 Ib N 0.3 lb N H ~ H I P Ocontains ~ (14/115) X 0.3 = 0.04 ib N, (31/115) X 0.3 = 0.08 lb P 1.1 lb (NH,).SO, contains (281132) X 1.1 = 0.23 lb N, (321132) X 1.1 = 0.27 lb S C
Nutrient - -1.7= Needed 0.50
N P S 1.0 0.08 0.27 3.4 = 7.1 = 3 = 7 0.14 0.03 0.01 A
A
Sulfur is praent in greatest excess of need and phosphorus is pre~entin least excess, closely followed by carbon.
Volume 49, Number 2, February 1972
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