F08%20EXAM%202%20comments - BioG 1101 Cornell University...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
BioG 1101 Exam 2 Comments 2008 Cornell University Cole Gilbert Nov. 4., 2008 1 EXAM 2 COMMENTS Average score = 29.7 out of a possible 46 points (= 64.5%) Standard deviation = 5.6 points (12%) This second prelim will count for about 24% (13 lectures) of your final grade in BioG 1101 Answers: (including alternate answers accepted in Bold ) 1) D 1 pt 12) E 1 pt 23) A 1 pt 34) D 1 pt 2) D 1 pt 13) D A 1 pt 24) A BE 1 pt 35) B 2 pts 3) D B 1 pt 14) A 1 pt 25) E 2 pts 36) B 1 pt 4) A B 1 pt 15) B 1 pt 26) D 1 pt 37) D 1 pt 5) C D 1 pt 16) D 1 pt 27) E 1 pt 38) B 1 pt 6) B 2 pts 17) C 1 pt 28) A 1 pt 39) C 1 pt 7) B 1 pt 18) E 1 pt 29) E 1 pt 40) B 1 pt 8) E 1 pt 19) A 1 pt 30) E 1 pt 41) C 1 pt 9) D 1 pt 20) C B 1 pt 31) A 1 pt 42) B 1 pt 10) E 1 pt 21) C 1 pt 32) B 2 pts 11) D ABE 1 pt 22) D 1 pt 33) C A 1 pt Comments on selected questions. 1. This question seeks an answer that does not support the argument that cells are open systems. More students answered C than chose the correct answer D. Choice C is, however, a characteristic of an open system. A closed system can not increase in order and complexity over time, as that would violate the 2 nd law of thermodynamics. Choice D is the best in that it describes a process that is true of cells, but it does not provide evidence that the cell is an open system. A closed system could also produce free energy in one part and use it in another part of the system. 2. Most students answered this one correctly, but a significant minority answered C, that one glucose molecule produces 3 CO2 molecules. Glucose is a 6 carbon molecule, therefore when the carbon is fully oxidized there are 6 CO2 molecules produced. 3. Endergonic reactions still have an activation energy that must be overcome (Choice D). It also prevents the reaction from slipping backward. The reaction will run this way, i.e., from products to reactants, because that is an exergonic reaction. It is spontaneous, but may be exceedingly slow. Therefore we will allow choice B as an alternate answer. Many students also answered D, that the uphill reaction musty be coupled to the synthesis of ATP to proceed. This is not the case. Examine the first 5 steps of glycolysis. All are uphill, but only two require ATP. They are coupled to the exergonic step 6 which pulls them through.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
BioG 1101 Exam 2 Comments 2008 Cornell University Cole Gilbert Nov. 4., 2008 2 4. This question asked which statement about an increase in the rate of hydrolysis of a solution of ATP was false. The sought answer was A. However, B, which suggested increasing the pressure, is also false. Increasing the pressure on a reaction involving gasses will increase the rate of reaction, but increasing the pressure has no effect on reactions of liquids or solids. Therefore, we will also accept B as an alternate answer. 5. This question asks about the fate of the components of pyruvate through the end of the
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 6

F08%20EXAM%202%20comments - BioG 1101 Cornell University...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online