Transcript CHAPTER 5 THE STRUCTURE AND FUNCTION OF MACROMOLECULES

CHAPTER 5
THE STRUCTURE AND
FUNCTION OF
MACROMOLECULES
Chapter 5 Objectives
After reading this chapter, completing the
study guide, and participating in class,
you should be able to:
1. List the levels of biological organization
from subatomic particles through
macromolecules
2. Describe the distinguishing
characteristics of carbohydrates and
explain their classification
3. Describe the important biological functions of
polysaccharides
4. Explain what distinguishes lipids from other
classes of biological macromolecules
5. Describe the unique properties, building blocks
and biological roles of fats, phospholipids and
steroids
6. Distinguish proteins from the other classes of
macromolecules and list the biological
functions which members of this class perform
7. List and be able to recognize the four major
components of a typical amino acid and
explain how amino acids may be grouped
according to the nature of their side chain
8. Identify a peptide bond and describe how
it is formed
9. Explain what determines protein
conformation and why it is important
10. Name the four levels of protein structure
and briefly describe from what aspect of
protein structure each is derived
11. Define denaturation and explain how
proteins may be denatured
12. Describe the characteristics that
distinguish nucleic acids from the other
classes of macromolecules
13. Summarize the functions of nucleic acids
14. Juggle three flaming batons...just
checking that you're still paying attention
(smile!)
15. List the major components of a
nucleotide and describe how these
monomers are linked together to form a
nucleic acid
16. Distinguish between a pyrimidine and a
purine and name those which occur in
nucleic acids.
17. Describe at least one function of
nucleotides other than their inclusion in
nucleic acids
18. Briefly describe the three-dimensional
structure of DNA
Introduction
• Cells join smaller organic molecules
together to form larger molecules.
• These larger molecules,
macromolecules, may be composed of
thousands of atoms and weigh over
100,000 daltons.
• The four major classes of macromolecules
are: carbohydrates, lipids, proteins, and
nucleic acids.
Polymer Key Principles
1. Most macromolecules are polymers
2. An immense variety of polymers can
be built from a small set of monomers
•
Pgs. 58-60
1. Most macromolecules are
polymers
• Three of the four classes of
macromolecules form chainlike molecules
called polymers (greek poly = many,
mer = parts).
– Polymers consist of many similar or identical
building blocks linked by covalent bonds.
• The repeated units are small molecules
called monomers (mono = one).
– Some monomers have other functions of their
own.
Making or Breaking Polymers
• The chemical mechanisms that cells use
to make and break polymers are similar for
all classes of macromolecules.
• See figure 5.2, pg 59
Making Polymers
• Monomers are connected
by covalent bonds via a
condensation reaction
or dehydration reaction.
– One monomer provides
a hydroxyl group and
the other provides a
hydrogen and together
these form water.
– This process requires
energy and is aided
by enzymes.
Breaking Down Polymers
• The covalent bonds
connecting monomers in a
polymer are disassembled by
hydrolysis.
– In hydrolysis as the covalent
bond is broken a hydrogen
atom and hydroxyl group from
a split water molecule
attaches where the covalent
bond used to be.
– Hydrolysis reactions
dominate the
digestive process,
guided by specific
enzymes.
2. An immense variety of polymers can
be built from a small set of monomers
• Each cell has thousands of different
macromolecules.
– These molecules vary among cells of the same
individual, even more among unrelated individuals of
a species, and are even greater between species.
• This diversity comes from various combinations
of the 40-50 common monomers and other rarer
ones.
– These monomers can be connected in various
combinations like the 26 letters in the alphabet can be
used to create a great diversity of words.
– Biological molecules are even more diverse.
Objective 1
• List the levels of biological organization
from subatomic particles through
macromolecules