Chem 147                   Midterm Examination                                             5 February 2010

 

 

First letter of your last name:  

 

Name:

                                                                            Last Name,                    First Name

 

 

 

Please CHECK that there are total of 4 pages (a total of 7 problems, which, with two, noted exceptions, are worth 15 pts each (for a total of 100 points) on the exam.

 

 

INSTRUCTIONS: 

 

 

1. All of the questions in this exam can be answered in one or two sentences or, in some cases, a short list.  I thus expect you to answer in the space provided.  (With so many students and no TA, IÕm forced to value brevity; you have been warned!).  Good luck!

 

 

 

2. Partial credit will be given for answers that are on the right track but not completely correct.  However, the ability to recognize when you do not know something is an invaluable scientific skill.  Therefore, if you are certain that you do not know enough about a given answer to receive at least 3 points partial credit, write ÒI DO NOT KNOWÓ (and only this) and you will receive 3 points partial credit.  (Note: this only holds for the entire question in multi-part questions.)

 

 

 

 

1.     Denote the places that each of the following elements is or was created.  Use ÒBBÓ to denote Big Bang, ÒSSÓ for Òstars smaller than the sun,Ó  ÒLSÓ for Òlarger stars, during normal fusion,Ó and ÒSNÓ for super nova.   Some elements may be created via more than one mechanism (20 pts)

 

 

 

He

 

 

 

Pb

 

 

 

U

 

 

 

O

 

 

 

P

 

 

 

H

 

 

 

S

 

 

 

Fe

 

 

 

C

 

 

 

N

 

  1. What role does the excited state resonance of the carbon nucleus play in the formation of carbon during stellar fusion?

 

 

 

 

 

 

 

 

 

 

 

 

3.     Of the nine planets (long live Pluto!) which are the two smallest?  Why are they so small?

 

 

 

 

 

 

 

 

 

 

 

 

4.     Is life on Earth reliant on the existence of plate tectonics?  If so, how?

 

 

 

 

 

 

 

 

 

 

 

 

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  1. Which types of protein-forming amino acids are not produced via Miller-Urey chemistry?

 

 

 

 

 

 

 

 

 

 

 

 

  1. The RNA world hypothesis seems appealing with respect to chemistry similar to that proposed (self-replicating RNAs) has been demonstrated in the laboratory.  Nevertheless, there are significant holes in the RNA world hypothesis regarding how the first self-replicating RNA might have arisen after the period of Miller-Urey chemistry.  What would you say is the most difficult unresolved problem?  Please argue your case. 

 

 

 

 

 

 

 

 

 

 

  1. Cairns-Smith is the ÒfatherÓ of the clay-world hypothesis.  Do we see any evidence for clay-based metabolism or genetics in us?  If so, where, and if not, what is Cairns-SmithÕs rationalization?  (5 pts)

 

 

 

 

 

 

 

 

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