BIOC223
This is a Tue, Wed, Fri course designed as a gateway course for Biological Majors taken in
second semester of either sophomore or junior year.
CARBOHYDRATES UNIT #1 PLAN:
WEEK 7 of the course
Overarching Course Objectives – Students will be able to
O1. Find, analyze, discuss, and evaluate scientific content in a primary literature or scientific
text that addresses a biochemical problem or claim
O2. Demonstrate effective and productive teamwork
O3. Communicate biochemical concepts to people within (peers and professor) and outside
(public) the field.
Carbohydrate Unit Objectives- Students will be able to
C1. Collect/obtain biochemical information from a variety of credible sources about
carbohydrates and present them using discipline appropriate representation.
C2. Describe specific chemical and physical properties/ features of a carbohydrate and
correlate elements of carbohydrate nomenclature and terminology with its structure.
C3. Given the name or chemical formula of a carbohydrate, draw both the Fisher and Haworth
representations of the carbohydrate and compare and contrast the two representations.
C4. Given the structure of a carbohydrate identify functionally important chemical features and
evaluate their roles in molecular recognition.
C5. Given the structure of a carbohydrate identify the covalent bond that joins the monomer
units and notate key features of the bond or macromolecule.
C6. Given the structure of a carbohydrate predict the impact of chemical reactions and/or
altering physical and chemical characteristics of the environment on the structure,
physicochemical properties, and the function of the carbohydrate and evaluate their impact on
molecular recognition.
C7. Given the structure of a chemically modified carbohydrate, identify the chemical
modifications and the modifying chemical reaction or given a specific chemical reaction create a
modified carbohydrate.
C8. Given the structures and functions of a variety of carbohydrates provide a
chemical/mechanistic explanation to how carbohydrates perform a diversity of functions within
biological systems by contextualizing specific structural features to explain specific functions.
C9. Given the structure of a carbohydrate or a carbohydrate binding another
compound/macromolecule, identify and analyze forces involved in intra- and inter-molecular
interactions.
C10. Given a figure and/or text depicting the key structural features of a macromolecular
assembly involving carbohydrates, hypothesize forces stabilizing the structure and design an
experimental test to evaluate the potential contributions of each force to stabilizing its structure.
Below is a detailed plan including all the planned activities and assessments for the first two
days of the week as well as a copy of the summative assessment given as an assignment at the
end of this week, due the Wed. of the following week to be discussed in class on the last Friday
of the two-week unit. The detailed plan and the corresponding activities/ assessments for the
rest of the week (mapped to the course objectives) is indicated on the caste top power point
slide.
Monday: (out of class)
Students are assigned the carbohydrates chapter of the text book and are required to complete
a low stake concept check quiz covering the reading material as a formative assessment. (C1a,
C2, C4)
Sample Questions from Concept Check:
Q1. Unmodified, simple sugars may contain the functional groups (indicate all that apply):
a. of an aldehyde
b. of a ketone
c. hydroxyl groups
d. amino group
Q2. The carbohydrate pictured is a
a. ketohexose
b. aldohexose
c. ketopentose
d. aldopentose
Is this a D or L sugar?
Tuesday: (in class)
Students complete Worksheet 1a: C2, C4, participate in an interactive lecture that covers new
material, complete Worksheet 1b: C3, C6a, do three think-pair share (TPS) questions (O2, O3,
C2, C3) and finish up the class with a low-stake formative wrap-up question (C2,C4) turned in
for grading on the material assigned in the reading and covered in class.
Worksheet 1a:
For the following three molecules:
a. Write down its chemical formula
b. Circle the chiral centers
c. Circle and name the different functional groups it contains
d. Suggest what physicochemical property(ies) that particular functional group would impart to
the molecule and what kind of chemical reactions they would participate in.
e. Based on the chemical properties you have considered suggest a categorization for the
biomolecule.
d. Draw a 4C, 5C and 6C version of this molecule and suggest a classification for these new
molecules.
Worksheet 1b:
a. If mannose is the C2 epimer of glucose, draw the Fisher (open) structure of L-mannose
based on your knowledge of the D-glucose structure. Make sure to clearly show your
reasoning through intermediate structures.
b. You have a mixture of α-L-mannose and β-L-mannose in aqueous solution. You add an
enzyme to this mixture that can only use the α-L-mannose as a substrate and cannot
react with β-L-mannose. After allowing the enzymatic reaction to proceed to completion
you find out that no β-L-mannose remains in the mixture. Briefly explain why the β−Lmannose was used up in this reaction.
Interactive Lecture slides:
Think-pair-share questions:
TPS1. In the monosaccharide derivatives know as sugar alcohols, the carbonyl carbon is
reduced to a hydroxyl group. For example, D-glyceraldehyde can be reduced to glycerol. Why is
there no designation of this sugar alcohol as D- or L-?
TPS2. Indicate one advantage of using Fisher over Haworth representation of monosaccharides
and one advantage of using Haworth over Fisher representation (i.e. what kind of information is
best communicated with each representation?)
TPS3. Why are the most stable conformations of sugars often nonplanar with hydrogens in the
axial positions? (Make sure you address both parts of the question that are underlined)
Wrap-Up Question:
a. Draw a representative ketohexose, where C-2 is the carbonyl of a ketohexose in its Fischer
representation.
b. Circle the carbon that specifies the D/L stereochemistry as well as the α/β stereo chemistry
c. Draw a Haworth projection of this molecule
d. Circle the carbon that specifies the D/L stereochemistry as well as the α/β stereo chemistry
e. What is the importance of the stereochemistry at these carbon centers for the structure and
function of the carbohydrate?
Summative Assessment given out after Friday Class:
Carbohydrates Assignment (Graded) (O1, O3, C1-C10)
(Given out at the end of Week 7 to be returned for the Wed of Week8)
Read the paper Weis, et.al. 1988 and answer the following 10 questions. Make sure to include
in your answers specific biochemical information either from other reputable sources (text
books, other primary literature etc) or directly from the paper.
1. Restate in your own words the specific biochemical question /problem the paper focused
on? (Comprehension)
2. Why is this question important? (Evaluation)
3. Restate in your own words the scientists’ hypothesis? (Comprehension)
4. What are the assumptions and/or preliminary knowledge that their hypothesis rest on?
(Knowledge, comprehension)
5. How do they go about testing it? Cartoon/ sketch out what do they actually do in the lab
to test it (Comprehension, application)
6. How did they present their findings? Compare and contrast the different experiments
and the corresponding findings presented in the paper? (Comprehension, Analysis)
7. What is the significance of their findings? (Evaluation)
8. What were their conclusions? (Comprehension)
9. Do you agree with their conclusions? Why or why not? (Did they take advantage of the
full scientific method? Did they have all the controls? Did they present or reference all
the data that led to their conclusions? Did they consider alternative explanations?)
(Analysis, Evaluation)
10. Is the original hypothesis of the paper tested to your satisfaction? (Evaluation)
If yes, use the conclusions of this work as preliminary data to define a follow up
question, a new hypothesis and design an experiment to test it. (Application, synthesis)
If no, propose an experiment to better test the stated hypothesis and discuss possible
interpretations of possible outcomes. (If you see a problem in the hypothesis, then first
better state the hypothesis and then design your experiment) (Application, Synthesis)