This document provides an overview of macromolecules including their structure, function, and importance in living organisms. It discusses the key macromolecules of carbohydrates, lipids, proteins, and nucleic acids. For each macromolecule, it describes the monomers used to build polymers, examples of different types, and their roles in cells. The document emphasizes that macromolecules are constructed through condensation reactions from simple monomers into complex polymers with unique properties essential for life.

1. Ch. 5 Structure and
Function of
Macromolecules
AP Biology

2. Macromolecules
• Most are polymers
• Polymer
– Large molecule consisting
of many identical or similar
building blocks linked by
bonds
• Monomer
– Subunits that serve as
building blocks for
polymers
Polyethene is a thermoplastic commodity heavily
used in consumer products (over 60 million tons are
produced worldwide every year).

3. A limitless variety of polymers can be
built from a small set of monomers
• Inherent differences between
siblings result from variations
in polymers
• Construction of
macromolecules
– 40-50 common monomers and
others that occur rarely
– Small molecules that are
common to all organisms are
ordered into unique
macromolecules

4. How Cells Use Organic
Compounds
• Biological organisms use the
same kinds of building blocks.
• All macromolecules (large,
complex molecules) have
specific functions in cells.
• Other than water,
macromolecules make up the
largest percent mass of a cell.

5. Condensation and Hydrolysis
• Condensation reactions
– Dehydration reactions
– When two molecules
become covalently
bonded to each other
through the loss of a small
molecule, usually water
• Hydrolysis
– Separation of two
molecules by the addition
of a water molecule

6. • Large polymers form from smaller
monomers.
• New properties emerge.
• Living cells require/synthesize:
– Carbohydrates
– Lipids
– Proteins
– Nucleic Acids
The Molecules of Life

7. • Used as fuel and building material
• Carbs are sugars and their polymers
• Main types:
– Monosaccharides
– Disaccharides
– Polysaccharides
Carbohydrates

8. Monosaccharides (CH2O)
• Generally have
molecular formulas in
some multiple of CH2O
• Glucose (C6H12O6) is
most common
• In aqueous solution
may form rings
• Major nutrients for cells

9. Disaccharides
• Two monosaccharides joined by glycosidic
linkages
• Glycosidic linkage
– A covalent bond formed between monosaccharides
• Sucrose is most prevalent

10. Dissacharide
Formation

11. Polysaccharides
• 100s to 1000s of
monosaccharides long
• Starch
– Storage poly. of plants
• Glycogen
– Storage poly. of animals
• Cellulose
– Structural poly. which is a major
component of tough plant cell walls
• Chitin
– Structural poly. used by arthropods
to build exoskeletons

12. Starch &
Cellulose
Forms ring in
aqueous
solution

13. Lipids
• Mostly hydrophobic
molecules with diverse
functions
• Little or no affinity for water
• Used for energy storage
and structure
• Main types:
– Fats
– Phospholipids
– Steroids

14. Fats
• Large molecules, but not
polymers
• Fatty acid
– A long carbon skeleton
with carboxyl group head
and a hydrocarbon tail
14

15. Triacylglycerol (Triglyceride)
• Three fatty acids
linked to one
glycerol molecule

16. Saturated & Unsaturated
Fats
• Saturated fatty acids
– Fatty acid containing no
double bonds between
the carbon atoms
composing the tail
– Solids at room temp.
• Unsaturated fatty acids
– Has one or more double
bonded carbons in the
tail

17. Phospholipids
• Two fatty acid tails linked to one glycerol
molecule
– Ambivalent behavior toward water
– When in contact with water they form a micelle
(cluster)

18. Steroids
• Lipids characterized by
a carbon skeleton,
consisting of 4
interconnected rings
• Cholesterol
– Important steroid that is a
common component of
the membranes of animal
cells
– Many hormones are
steroids produced from
cholesterol

19. Proteins
• The molecular tools for most cellular
functions
• Used for:
– Structural support
– Storage
– Transport of other substances
– Signaling from one part of the organism to the
other
– Movement
– Defense against foreign substances
• Conformation
– Unique 3-D shape of a protein

20. Protein Polypeptides
• Polymers of amino
acids connected in a
specific sequence
• Amino acids
– Organic molecules
possessing both
carboxyl and amino
groups
• Acidity is determined
by side chains

21. Peptide Bonds
• Formed when an
enzyme joins amino
acids by means of
condensation
• Polypeptide
– Chains of amino acids
linked by peptide
bonds

22. • Conformation (shape) determines function
and is the result of the linear sequence of
amino acids in a polypeptide.
• Folding, coiling and the interactions of
multiple polypeptide chains create a
functional protein
• 4 levels of conformation
– Primary
– Secondary
– Tertiary
– Quartinary
Protein Conformation

23. Primary Structure
• Unique, linear
sequence of amino
acids in a protein
• A change in one a.a.
can effect every other
level of structure
– ex. point mutation in
hemoglobin

24. Secondary Structure
• Hydrogen bonding
occurs between amino
and carbonyl groups
of amino acids.
• Structures Formed:
• α Helix: Common in fibrous
proteins, creates “elastic”
properties.
• β Sheet: Anti-parallel
chains form sheet.

25. Tertiary Structure
• Irregular contortions from bonding
between side chains of various amino
acids
25

26. Quartinary Structure
• Overall protein structure that results
from aggregation of tertiary subunits

28. Denaturation
• Unraveling and loss of native
conformation of a protein
• Can be due to heat, pH, salts, etc.
• Some can renature exactly, others
cannot
• Ex: cooking an egg

29. Nucleic Acids
• Store and transmit hereditary information
• Gene
– A unit of inheritance
• DNA & RNA
– Deoxyribonucleic acid & Ribonucleic acid
– DNA is like computer software, proteins are like
hardware
– Genetic info flows from DNA  RNA  protein

30. DNA Structure
• A polymer with an
information-rich sequence
of nucleotides
• Pyrimidine
– 6 membered ring made of
carbon and nitrogen atoms
– Cytosine and thymine
• Purine
– 6 membered ring fused to a
five membered ring
– Adenine and guanine
• Phosphodiester
– Covelent bonds holding
nucleotides together

31. DNA Structure, cont.
• Double helix
– Two chains of nucleotides
that spiral around an
imaginary axis
• Hydrogen bonds
– Hold two chains of
nucleotides together
• Adenine pairs with
thymine
• Cytosine pairs with
guanine
• Two strands of DNA
double helix are
complimentary

32. RNA
• Single stranded
• Four kinds of
nucleotide monomers
(A, U, C, G)
• Key players in the
protein-building
processes
• mRNA, tRNA, rRNA

33. DNA & Protein Importance
• Inheritance is based on precise
replication of DNA
• We can use DNA and proteins as “tape
measures” of evolution
– Linear sequences of nucleotides in DNA
molecules are passed from parents to
offspring
– More distantly related species have chains
that are less similar

34. Review questions
• Section 4.1 page 59, number 1
• Read Inquiry 4.2. Think about the what if question.
• Section 5.1 page 69, number 1
• Section 5.2 page 74, number 3
• Self quiz page 91 numbers 1-8.