Enduring understandings: Unit 4 concerned the structures, chemical properties and
biological functions of nucleotides and nucleic acids. All six of the course EUs were
relevant to this unit. In order to demonstrate your ability to see the big picture of the
course, and how this unit fits into that big picture, chose 2 of the 6 EUs stated below and
give a specific example to explain each, drawing, on what you've learned in this unit
about nucleotides and/or nucleic acids.
1. The study of chemistry can be summarized as the study of electrostatic attractions
and repulsions between charged objects. The strengths of these forces depend on
both the size of the charges involved and on the distance between them, according
to Coulomb's Law.
2. Learning and communicating about chemistry is highly dependent on
understanding chemical symbolism and ways of representing ideas. Molecules
can be represented in many ways, and each representation has its own strengths
and weaknesses. Therefore, the appropriate representation to use in a given
context depends on what you are trying to get across about the molecule in
question.
3. Living organisms are complex systems composed of interdependent chemical
structures and processes, and therefore can be understood at a molecular level
using the same chemical principles that apply to non-living objects. Most of the
important chemical processes and species that occur in living things are based on
the chemistry of carbon, which is traditionally called organic chemistry.
4. The electron arrangement within a molecule determines its shape and polarity and
therefore its interactions with other molecules, which determine its physical
properties.
5. The electron arrangement within a molecule also determines its stability and
therefore its chemical properties. Chemical reactions can be analyzed in terms of
the energetic stability of the reactants and products.
6. Biological chemistry is a very new science, and is constantly advancing.
Advances in technology and new theoretical insights have pushed the science
forward rapidly over the past 50 years, but there is still much we don't know
about the chemical processes of living things. We expect that some of what we
think we know now will change in the future.
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