AP BIOLOGY
(SECONDARY)
ESSENTIAL UNIT 1 (E01)
(BIOCHEMISTRY)
(July 2012)
Unit Statement:
In this unit the student will focus on the major biological macromolecules: their structure,
function, interaction with other molecules. An important theme addressed is how changes in
structure affect function in these molecules, particularly proteins. For some students, a
review of the earlier chemistry chapters in the text may be necessary as a precursor to these
unit outcomes.
Essential Outcomes:
1. The Student Will relate water’s polarity and hydrogen bonding with its properties of
cohesion, adhesion, and high specific heat capacity, and its role as a solvent. (3.1-3.3)
(2.A.3.a.3)
2. TSW recognize that carbon is used to build carbohydrates, proteins, lipids, and nucleic
acids that may play storage or structural roles; that nitrogen is used to build proteins
and nucleic acids; and that phosphorous is used to build nucleic acids and certain
lipids. (4.1-4.3 for background in organic chemistry; 4.3 for key biologically
important chemical groups; 5.1-5.5 for large biological molecules) (2.A.3.a.1&2)
3. TSW recognize that genetic information is stored in and transmitted from one generation
to the next through DNA and, in some cases, RNA. (5.5, 19.2) (3.A.1.a.1)
4. TSW recognize that DNA and RNA molecules have similarities and differences that
influence their function. (5.5) (3.A.1.b)
5. TSW describe the structure of DNA and RNA including the three principal parts of a
nucleotide, the arrangement of nucleotides in a linear, covalently bonded molecule
with 3’ and 5’ ends, and with the nitrogenous bases perpendicular to the sugarphosphate backbone. (5.5) (3.A.1.b.1)
6. TSW identify the basic structural difference between DNA and RNA. (5.5) (3.A.1.b.2)
(See outcome statement notes.)
7. TSW recognize that structure and function of polymer macromolecules follow from the
way their monomers are assembled. (5.1) (4.A.1.a)
8. TSW explain how biological information is encoded in the sequences of nucleotide
monomers (both DNA and RNA) that are themselves composed of structural
components that give them specific properties. Further, TSW recognize that the
differences in structure between DNA and RNA account for their differing
functions. (5.5) (4.A.1.a.1) (also LO 4.1) (SP 7.1) (See outcome statement notes.)
9. TSW explain how, in proteins, the specific sequence of amino acids in a polypeptide
(primary structure) interacts with the polypeptide’s environment to determine its
overall shape (secondary, tertiary, and quaternary structure). Further, TSW
recognize that the R groups of amino acids can be categorized by their chemical
properties, and that it is the interactions of these R groups that determine localized
structure and function. (5.4) (4.A.1.a.2) (also LO 4.1) (SP 7.1) (See outcome
statement notes.)
10. TSW explain that though lipids are generally nonpolar, phospholipids have a polar
region which can interact with other polar molecules or water, and a nonpolar region
whose structural properties and function are related to differences in saturation.
(5.3) (4.A.1.a.3) (See outcome statement notes.)
11. TSW explain that carbohydrate polymers are composed of sugar monomers whose
structure and bonding by dehydration synthesis to one another determine the
structural properties and functions of the polymer. Illustrative examples of which
include cellulose vs. starch. (5.2) (4.A.1.a.4) (also LO 4.1) (SP 7.1) (See outcome
statement notes.)
12. TSW explain how directionality in nucleic acids arises from the 5’ and 3’ carbons of the
sugar in the nucleotide and that this directionality determines the direction in which
DNA synthesis and transcription occur. (5.5) (4.A.1.b.1)
13. TSW recognize that proteins have an amino (NH2) and a carboxyl (COOH) end as a
result of peptide bonds formed by dehydration synthesis between the amino and
carboxyl groups of linearly arranged amino acids. (5.4) (4.A.1.b.2)
14. TSW recognize that the secondary structure of carbohydrates is determined by the nature
of the bonding between carbohydrate monomers and their resultant orientation in the
carbohydrate. (5.2) (4.A.1.b.3)
15. TSW utilize representations or models to explain how the subcomponents of a biological
polymer and the sequence of these components help to determine the properties of
that polymer. (5.2-5.5) (LO 4.2) (SP 1.3) (See suggested assessment tools and
strategies.)
16. TSW utilize models to predict and justify that changes in the subcomponents of a
biological macromolecule can affect the function of the molecule. (5.2-5.5) (LO
4.3) (SP 6.1, 6.4) (See suggested assessment tools and strategies.)
17. TSW recognize that a change in the structure of a molecule may result in a change of the
function of the molecule. (e.g. 5.4 inter alia) (4.B.1.a) (See outcome statement
notes.)
18. TSW explain using evidence how variations within classes of molecules allows for a
greater diversity of functions. (5.1-5.5) (4.C.1.a) (LO 4.22) (SP 6.2) (See outcome
statement notes.)
19. TSW actively engage in laboratory exercises that fulfill the College Board requirements
for 2 labs in each of the 4 big idea areas as directed by the instructor.
Outcome Statement Notes:
1. The instructor may use one or more of these illustrative examples or another to promote
student understanding of this concept: cohesion, adhesion, high specific heat capacity,
universal solvent supports reactions, heat of vaporization, heat of fusion, water’s thermal
conductivity. (3.1-3.3) [TSW 1]
2. Specifically, College Board has identified four differences that should be taught: DNA
contains deoxyribose while RNA contains ribose, RNA contains uracil in place of thymine
in DNA, DNA is usually double stranded while RNA is usually single stranded, and the
two DNA strands are antiparallel in directionality with respect to 5’ and 3’. [TSW 6]
3. College Board states that the molecular structure of specific nucleotides, amino acids,
lipids, and carbohydrates is beyond the scope of the course and the AP Exam. [TSW 8 –
TSW 11]
4. This TSW is nonspecific and can be illustrated with any type of large biological molecule,
though change in protein shape is a major recurring topic in the course. [TSW 16]
5. The instructor may use one or more of these illustrative examples or another to promote
student understanding of this concept: different types of phospholipids in cell membranes,
different types of hemoglobin, MHC proteins, chlorophylls, antibody diversity. (This
TSW also meets the learning objective LO 4.22.) [TSW 18]
Suggested Assessment Tools and Strategies:
1. Students can use molecular model kits to build 3-dimensional representations of
biologically important functional groups, carbohydrates, nucleic acids, proteins, or lipids.
To build the large molecules, many sets will be required. Alternatively, other materials
may be used to construct larger molecular models. (Watson and Crick used chicken wire!)
[TSW 2]
2. A summative activity may be Acivity 4.2/5.2 Test Your Understanding in Practicing
Biology. This activity relates structure and functional properties and reflects the theme of
emergent properties in Big Idea 4. [TSW 7-TSW 11]
3. Illustrations, molecular models, or other materials that would allow students to arrange and
rearrange components of various polymers to gain an understanding of the relation
between structure and function in biological polymers could be used. [TSW 15]
4. Molecular model kits can be used to explore how changes in the subcomponent structure of
a macromolecule can affect its function. [TSW 16]