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Chapter 3: Molecules of life
Name______________
1. Explain the role of carbon in the molecular diversity of life. Include its atomical structure,
bonding patterns, and role in a variety of hydrocarbon structures.
2. Define polymer and monomer.
3. Describe what happens in a condensation reaction. (Draw a sketch of fig 3.6 or attach from
internet)
4. Describe what happens in a hydrolysis reaction. (Draw a sketch of fig 3.6 or attach from
internet)
5. Complete the following table: (Use pg. 48 and pg.36) (just pick a few examples for each)
Fill as best as you can.
Molecules of Life
Macromolecule
group
Carbohydrates
Lipids
Protein
Major
SubCategories
Elements Present
(Functional
groups)
Biological
Function
Common
Examples
CARBOHYDRATES
6. What is the common name for carbohydrates? What suffix is a clue that you are dealing with
a carbohydrate?
7. Carbohydrates perform three primary functions for cells. They are:
A.
B.
C.
8. Compare and contrast monosaccharides, disaccharides, and polysaccharides
9. Name two VITALLY IMPORTANT monosaccharides
A.
B.
10. Monosaccharides, especially ______________, are the source of ___________ for cellular
work. In addition, the carbon skeletons of monosaccharides provide the
_____________________ for building other organic molecules like amino acids and fatty
acids.
11. What are the 3 most common polysaccharides and what is their role in different organisms?
12. The most abundant organic compound on earth is a structural polysaccharide produced by
plants. Name it.
13. Even though starch and cellulose and chemically similar, humans can digest starch but not
cellulose. Explain why this is true.
14. Where is the polysaccharide chitin commonly found? What is the most significant
molecular difference between the monomers of chitin and the monomers of starch, glycogen,
and cellulose?
Lipids
1. Lipids are not technically polymers. They vary greatly in structure & function. What trait
unites all lipids and what structural characteristic accounts for this property?
2. Name the three most biologically important families of lipids.
A.
B.
C.
3. Fats are known as triglycerides or triacylglycerols. Describe the chemical composition of a
fat.
4. Use the chart below to compare and contrast (include a picture!) of saturated and unsaturated
fats.
Saturated Fats
Unsaturated Fats
5. A diet rich in saturated fats can lead to cardiovascular disease. Why do we need fats at all?
6. How is the structure of a phospholipid molecule different from that of a triglyceride
molecule?
7. Describe how phospholipids behave when they are in contact with water. Why is this such a
great adaptation for the structural molecules of plasma membranes?
8. Cholesterol is a vital steroid. Explain its critical importance to vertebrates.
PROTEINS******
1. What is the monomer of a protein? What is its chemical structure? Which components are
included when referring to the backbone of a polypeptide?
2. What is the major difference between the 20 amino acids of proteins? (See appendix V in the
back)
3. What is the reaction by which polypeptides are formed? What is the resulting bond called?
4. What is meant by primary structure of proteins?
5. What type of bonding contributes to the secondary structure of proteins?
6. What types of bonds or interactions contribute to the tertiary structure of proteins?
7. What is meant by quaternary protein structure?
8. What is the difference between a protein and a polypeptide?
9. What is the impact of a single variation (one wrong amino acid) in the amino acid sequence
of a polypeptide? Provide an example.
10. What is the impact of extreme temperature or pH on protein structure? How does that
impact protein function? Is this situation reversible?
NUCLEIC ACIDS
1. The monomers of nucleic acids (DNA and RNA) are called ___________________. The 3
parts of the monomers are
A.
B.
C.
2. What does ATP stand for and what are its structural components? Drawing a sketch will be
helpful.
3. What role do hydrogen bonds play in the DNA molecule?
4. How does RNA differ from DNA?