SC 135 - Second Exam Spring 2011


Links connect to relevant parts of the online book.





On the line to the left, place the letter of the choice that best  answers the question.  Three Points Each.

      NOTE:  "e" answers are never the correct answer.





1.   What is the proper difference?

_______                a.  RNA is much longer than DNA                                             b.  RNA is double-stranded, DNA is single-stranded

c.  RNA is single-stranded, DNA is double-stranded                    d.  RNA is a carbohydrate, DNA is a protein

                                                    e.   RNA can take DNA=s lunch money




2.   Lipids act as water barriers because they


_______                a.  Are hydrophobic                                     b.  Are hydrophilic                        c.  Do dehydration synthesis

                             d.  Aren=t digestible                                                    e.  Never got the skills for a better-paying career




3.    Two atoms of the same element are triple-bonded to each other.  The element is


_______                a.  Naturally radioactive                 b.  Found in column 5               c.  Found in column 3                 d.   Hydrophobic

                                                    e.  A little kinky




4.   Why aren=t electron microscopes generally used to look at living cells?

_______                a.  Cells are too small to see                       b.  No one can afford it                        c.  Specimens are put in a vacuum

                            d.  Beam is too small                                                        e.  >Cause until now, nobody thought of it.




5.   If a large molecule is broken down to bits, what process is involved?


_______                a.  Dehydration digestion                b.  Dehydration synthesis                c.  Polarity distribution                   d.  Hydrolysis

                                            e.  It involves calling the large molecule nasty names




6.    A allele is


_______                a.  A variant gene sequence                b.  A protein with a different function                c.  Always made of RNA

                            d.  All of these                                                            e.  Kind of a weird word





7.    At which Celsius temperature would water be most dense?


_______                a.  100o                       b.  4o                           c.  0o                           d.  -25o

            e.  Isn=t water pretty dumb at any temperature?





8.   The tiniest gap visible allows the measurement of


_______                a.  Magnification                b.  Ultrastructure                c.  Resolution            d.  Beam spread                e.  Jean tightness






9.    Radioactivity is directly connected to the number of  ______ in an atom.


_______                a.  Neutrons               b.  Protons                 c.  Electrons                d.  Photons                    e.  Electrical outlets






10.   Actin is a


_______                a.  Lipid used in barriers                b.  Protein used in movement                    c.  Carbohydrate used in energy storage

d.  Nucleic acid found in bacteria                                e.  Thing done on stage in Alabama






11.   In a gene, the ratio of nucleotides to amino acids in the protein is


_______                a.   One to one                       b.  Four to one                       c.  Two to one                    d.   Three to one

                                                                                        e.   A scootch to a zillion






12.    Since anti-oxidants prevent oxidation, they would prevent


_______                a.  Electrons being added to compounds                                    b.  Electrons being stolen from compounds

c.  Oxygen being added to compounds                                      d.  Oxygen being pulled off of compounds

                                                            e.  It all sounds pretty violent





Answer any eight of the following questions for 4 Points Each.

Note:  if you answer more than eight, only the first eight  will be corrected.

You can get partial credit on these answers.


1.    Briefly explain why individual water molecules have to be very hot to evaporate.




2.    What happens on the two ends of an antibody molecule?


3.    Here is a chemical reaction.  Give the general terms (do not give the names of the compounds!) here that would apply to any similar reaction.

CO2        +        H2O                   light        >         C6H12O6      +         O2


        __________   __________        ___________           __________             ___________

4.     Why would some specimens have to be sectioned?



5.    For a molecule to be considered organic, it must have -



6.   Much of our DNA is not genes.  What are two different things that non-coding DNA is?


7.   Why, exactly, does Carbon dating not work well on things older than 50000 years?



8.   How are isotopes of the same elements different?



9.    What are two different classes of molecules that are polymers?


10.   Give examples of these two properties of water in action -




11.   Why can lipids make especially good poisons?



12a.   Which bond type can have many different strengths in a single molecule?



Why does the strength vary?



13.   What are the two types of pieces in a lipid molecule?


14.   What are two different features that aspartate carbamoyltransferase would have?






Answer any four of the following questions for Eight Points Each.

Note:  if you answer more than four, only the first four will be corrected.

You can get partial credit on these answers.


1.   Name and give a brief description for the four levels of protein structure.








2.   Microscopes can be split into two main groups based upon either listed feature.  For each feature, name the groups.

Nature of the

Imaging Beam -


Interaction of Beam

with specimen -


3.   How many





# 35

Column 7


How many

electrons? (Radical form)

How many



ion form?

4.   What are four different types of communication molecules?




5.   For carbohydrates - 


that makes

most of them -


Two main

forms -




that make

them -

6.  Using the numbers of bonds as a guide, fill in the symbols for either Carbon, Hydrogen, Nitrogen, or  Oxygen.


Like in class, there was a molecule drawn with the bonds shown connecting the mystery atoms.


7.    For the pH scale shown below, fill in the proper blanks -


                                          2     3     4     5     6     7     8     9     10    11    12    13



           Name                     _________________     _____________    ____________________



             Ion                         _______________                                   ____________________ 


Link to Answer Key



Answer as many as you are able.  Wrong answers will not result in points being lost from the main exam.   You can get partial credit on these answers.


Why was the concept of atomic mass units invented?  Three Points.



Why exactly does alpha radiation only affect surface cells?




What known system was used as a starting point for understanding electrons on atoms?  Three Points.




What free radical is most likely damaging your cells right now?  Three Points.




What is a hydration shell?   Three Points.




What very good thing happens to a lake when it turns over?  Three Points.




Why is there no such thing as absolutely pure water?  Three Points.




Why do plants produce starches that are easy to break down?  Three Points.




What is a ribozyme?  Three Points.



How is an electron beam focused?  Three Points.





Michael McDarby.

SC 135

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