Download Chapter_5

• Unit 2: Pre-test
– Avg = 5 (out of 23)
– Range = unknown
• Termites
– Follow Paper Mate ink
– Acts as a pheromone
• Test corrections – due tomorrow
• I will scream sometime during class today.
Chapter 5
The Structure and Function of
Macromolecules
Chapter 5 The Structure and Function of
Macromolecules
1.
What are the 4 major macromolecules?
–
–
–
–
2.
Carbohydrates
Proteins
Lipids
Nucleic acids
How are they all similar?
–
–
All large polymers made of smaller monomers
All formed the same way
Figure 5.2 The synthesis and breakdown of polymers
HO
1
3
2
H
Unlinked monomer
Short polymer
Dehydration removes a water
molecule, forming a new bond
HO
Figure 5.2A
1
H
HO
2
H2O
3
4
H
Longer polymer
(a) Dehydration reaction in the synthesis of a polymer
HO
1
2
3
4
H
Hydrolysis adds a water
molecule, breaking a bond
HO
1
2
3
H
H2O
HO
Figure 5.2B (b) Hydrolysis in the breaking down of a polymer
H
Chapter 5 The Structure and Function of
Macromolecules
1.
2.
3.
What are the 4 major macromolecules?
How are they all similar?
What are carbohydrates & what are they made of?
–
–
Sugars
Made of monosaccharides
•
•
•
•
CH20
Sugars end in -ose
Nutrient for cells (1° glucose)
Carbon skeleton is used for other organic molecules
Figure 5.3 Examples of monosaccharides
Triose sugars Pentose sugars
(C3H6O3)
(C5H10O5)
H
O
H
Aldoses
C
O
H
O
C
C
OH
H
C
OH
H
C
OH
H
C
OH
H
C
OH
HO
C
H
C
OH
H
H
C
OH
H
H
H
H
C
H
C
OH
H
HO
C
H
C
OH
HO
C
H
H
C
OH
H
C
OH
H
C
OH
H
C
OH
H
H
Glucose
Galactose
H
C OH
H
C
O
H
C OH
H
C OH
C
O
O
C OH
H
C OH
HO
H
H
C OH
H
C OH
Dihydroxyacetone
H
C OH
H
C OH
H
H
C OH
H
Ribulose
O
C
H
Ribose
Ketoses
H
C
Glyceraldehyde
Figure 5.3
Hexose sugars
(C6H12O6)
C H
H
Fructose
Figure 5.4 Linear & ring forms of glucose
O
H
1C
H
HO
2
3
C
6CH
OH
C
H
H
C
5
5C
H
H
4
H
2OH
6
C
H
OH
4C
OH
OH
OH
O
3
C
H
2C
2OH
5C
H
H
OH
C
6CH
O
H
H
4C
1C
CH2OH
O
OH
H
OH
3C
6
H
1C
H
2C
4
HO
H
OH
3
OH
H
H
1
2
OH
OH
H
H
O
5
OH
OH
H
Figure 5.4 (a) Linear and ring forms. Chemical equilibrium between the linear and ring
structures greatly favors the formation of rings. To form the glucose ring,
carbon 1 bonds to the oxygen attached to carbon 5.
Chapter 5 The Structure and Function of Macromolecules
1.
2.
3.
4.
What are the 4 major macromolecules?
How are they all similar?
What are carbohydrates & what are they made of?
How are monomers added to carbs?
(a) Dehydration reaction
in the synthesis of
maltose. The bonding
of two glucose units
forms maltose. The
glycosidic link joins
the number 1 carbon
of one glucose to the
number 4 carbon of
the second glucose.
Joining the glucose
monomers in a
different way would
result in a different
disaccharide.
CH2OH
CH2OH
H
O
H
OH H
HO
H
H
H
OH
HO
O
H
OH
H
OH
H
OH
CH2OH
H
OHOH
H
O
H
OH H
HO
CH2OH
H
1–4
1 glycosidic
linkage
Glucose
4
O
H
OH H
H
H
OH
Maltose
H
OH
O
H2O
Glucose
H
OH
Chapter 5 The Structure and Function of Macromolecules
1.
2.
3.
4.
5.
What are the 4 major macromolecules?
How are they all similar?
What are carbohydrates & what are they made of?
How are monomers added to carbs?
What are polysaccharides used for?
–
Energy storage
•
•
–
Starch – plants
Glycogen – animals
Structural support
•
•
Cellulose
Chitin
Chapter 5 The Structure and Function of Macromolecules
Chloroplast
Starch
Mitochondria
Giycogen granules
0.5 m
1 m
Amylose
Amylopectin
(a) Starch: a plant polysaccharide
Glycogen
(b) Glycogen: an animal polysaccharide
H
H
4
CH2O
H
O
H
OH H
H
OH
HO
H
OH
 glucose
(a)
O
CH2O
H
O
H
OH H
C
H
C
OH
H
HO
C
H
4
H
C
OH
H
C
OH
H
C
OH
OH
1
HO
H
H
OH
 glucose
 and  glucose
ring structures
CH2O
H
O
CH2O
H
O
HO
4
1
OH
O
CH2O
H
O
HO
(c) Cellulose: 1– 4 linkage
of  glucose monomers
1
OH
6. Why do we poop corn?
4
OH
O
CH2O
H
1
OH
O
4
OH
O
OH
OH
O
OH
CH2O
H
O
O
1
OH
OH
OH
O
OH
4
O
OH
OH
(b) Starch: 1– 4 linkage of
 glucose monomers
1
OH
CH2O
H
O
CH2O
H
O
OH
O
CH2O
H
OH
Chapter 5 The Structure and Function of Macromolecules
Cellulose microfibrils
in a plant cell wall
Cell walls
Microfibril
About 80 cellulose
molecules associate
to form a microfibril, the
main architectural unit
of the plant cell wall.
0.5 m
Plant cells
OH CH2OH
OH
CH2OH
O O
O O
OH
OH
OH
OH
O
O O
O O
CH
OH
OH
CH2OH
2
OH
Parallel cellulose molecules are
held together by hydrogen
bonds between hydroxyl
groups attached to carbon
atoms 3 and 6.
CH2OH
OH CH2OH
OH
O O
O O
OH
OH
OH
OH
O
O O
O O
OH CH2OH
OH CH2OH
CH2OH
OH
OH CH2OH
O O
O O
OH
OH
OH O
O OH
O O
O
CH
OH
OH
CH
OH
2
2OH
 Glucose
Figure 5.8 Cellulose
monomer
Cellulose
molecules
A cellulose molecule
is an unbranched 
glucose polymer.
Chapter 5 The Structure and Function of Macromolecules
H
OH
CH2OH
O OH
H
OH H
H
H
NH
C
O
CH3
(a) The structure of the
chitin monomer.
(b) Chitin forms the exoskeleton
of arthropods. This cicada
is molting, shedding its old
exoskeleton and emerging
in adult form.
(c) Chitin is used to make a
strong and flexible surgical
thread that decomposes after
the wound or incision heals.
Chapter 5 The Structure and Function of Macromolecules
1.
2.
3.
4.
5.
6.
7.
What are the 4 major macromolecules?
How are they all similar?
What are carbohydrates & what are they made of?
How are monomers added to carbs?
What are polysaccharides used for?
Why do we poop corn?
What are some common lipids?
–
–
–
–
–
Fats
Phospholipids
Steroids
Oils
Waxes
Chapter 5 The Structure and Function of Macromolecules
1.
2.
3.
4.
5.
6.
7.
8.
What are the 4 major macromolecules?
How are they all similar?
What are carbohydrates & what are they made of?
How are monomers added to carbs?
What are polysaccharides used for?
Why do we poop corn?
What are some common lipids?
How are fats made?
Figure 5.11 The synthesis and structure of a fat, or
triacylglycerol
H
H
C
O
H
C
OH
HO
H
H
C
C
C
H
OH
H
C
H
H
C
H
H
C
H
H
H
C
C
H
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
Fatty acid
(palmitic acid)
OH
H
Glycerol
(a) Dehydration reaction in the synthesis of a fat
Ester linkage
O
H
H
C
O
C
H
C
H
O
H
C
O
C
H
C
H
O
H
C
H
O
C
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
(b) Fat molecule (triacylglycerol)
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
C
H
H
H
C
H
H
H
C
H
H
H
C
H
H
Chapter 5 The Structure and Function of Macromolecules
1.
2.
3.
4.
5.
6.
7.
8.
9.
What are the 4 major macromolecules?
How are they all similar?
What are carbohydrates & what are they made of?
How are monomers added to carbs?
What are polysaccharides used for?
Why do we poop corn?
What are some common lipids?
How are fats made?
What is the difference between a saturated &
unsaturated fat?
Figure 5.12 Examples of saturated and unsaturated fats
and fatty acids
Stearic acid
(a) Saturated fat and fatty acid
Oleic acid
(b) Unsaturated fat and fatty acid
cis double bond
causes bending
Staple test corrections to test & place in box
Saturated vs Unsaturated Fats
-
No double bonds (C-C)
Carbons are saturated
Solid at RT
Animal fats
Butter
Bacon grease
What are trans fats?
- Formed by hydrogenation
- C=C without the “kink”
- Double bonds (C=C)
- Carbons not saturated
- Oil at RT
- Plant or fish fats
- Vegetable oil
- Olive oil
Saturated vs Unsaturated Fats
-
No double bonds (C-C)
Carbons are saturated
Solid at RT
Animal fats
Butter
Bacon grease
What are the functions of fats?
- Energy storage (2X carbs)
- Cushion
- Insulation
- Double bonds (C=C)
- Carbons not saturated
- Oil at RT
- Plant or fish fats
- Vegetable oil
- Olive oil
Figure 5.13 The structure of a phospholipid
+N(CH )
CH2
3 3
Choline
CH2
O
O
P
–
O
Phosphate
Amphipathic – molecules
both polar & non-polar
O
CH2
CH
O
O
C
O C
CH2
Glycerol
O
Fatty acids
Hydrophilic
head
Hydrophobic
tails
(a) Structural formula
(b) Space-filling model
(c) Phospholipid
symbol
Figure 5.14 Bilayer structure formed by self-assembly of
phospholipids in an aqueous environment
WATER
Hydrophilic
head
WATER
Hydrophobic
tail
Figure 5.15 Cholesterol, a steroid
H3C
CH3
CH3
HO
CH3
CH3
Chapter 5 The Structure and Function of Macromolecules
10. What are the monomers of proteins?
Amino acids
11. How are all amino acids similar?
 carbon
R
O
H
N
C
C
OH
H
H
Amino
group
Carboxyl
group
Figure 5.17 The 20 amino acids of proteins
CH3
CH3
H
H3N+
C
CH3
O
H3N+
C
H
Glycine (Gly)
O–
C
H3N+
C
H
Alanine (Ala)
O–
CH
CH3
CH3
O
C
CH2
CH2
O
H3N+
C
H
Valine (Val)
CH3
CH3
O–
C
O
H3N+
C
H
Leucine (Leu)
H3C
O–
CH
C
O
C
H
Isoleucine (Ile)
O–
Nonpolar
CH3
CH2
S
NH
CH2
CH2
H3N+
C
H
CH2
O
H3N+
C
O–
Methionine (Met)
C
H
CH2
O
H3N+
C
C
O–
Phenylalanine (Phe)
H
O
H2C
CH2
H2N
C
O
C
O–
H
C
O–
Tryptophan (Trp)
Proline (Pro)
OH
OH
Polar
CH2
H3N+
C
CH
O
H3N+
C
O–
H
Serine (Ser)
C
CH2
O
H3N+
C
O–
H
C
CH2
O
C
H
O–
H3N+
C
O
H3N+
C
O–
H
Electrically
charged
H3N+
CH2
C
H3N+
O–
C
NH3+
O
C
CH2
C
CH2
CH2
CH2
CH2
CH2
CH2
O
CH2
C
O–
H
H3N+
C
O
CH2
C
H
O–
H3N+
C
H
O–
H
Glutamic acid
(Glu)
NH+
C
O–
Lysine (Lys)
NH2+
H3N+
CH2
O
CH2
H3N+
C
H
Aspartic acid
(Asp)
O
C
Glutamine
(Gln)
NH2
C
C
C
Basic
O–
O
O
Asparagine
(Asn)
Acidic
–O
CH2
CH2
H
Tyrosine
(Tyr)
Cysteine
(Cys)
Threonine (Thr)
C
NH2 O
C
SH
CH3
OH
NH2 O
NH
CH2
O
C
C
O–
H
O
C
O–
Arginine (Arg)
Histidine (His)
Chapter 5 The Structure and Function of Macromolecules
10. What are the monomers of proteins?
11. How are all amino acids similar?
12. How are amino acids connected?
Dehydration (condensation) rxn
Creates a peptide bond
Figure 5.18 Making a polypeptide chain
Peptide
bond
OH
CH2
SH
CH2
H
N
H
OH
C C
CH2
H
H
N C C OH H
N C
H O
H O
H
(a)
C OH
O
DESMOSOMES
H2O
OH
DESMOSOMES
DESMOSOMES
OH
CH2
H
H N C C
H O
(b)
Amino end
(N-terminus)
Side chains
SH
Peptide
CH2 bond CH2
H
H
N C C
H O
N C C
H O
Carboxyl end
(C-terminus)
OH
Backbone
Chapter 5 The Structure and Function of Macromolecules
10. What are the monomers of proteins?
11. How are all amino acids similar?
12. How are amino acids connected?
13. What are the 4 levels of protein structure?
1° (Primary) – aa sequence (determined by DNA sequence)
2° (Secondary) – based on H-bonds
3° (Tertiary) – overall globular shape – 3D structure
4° (Quaternary) – several 3° polypeptides (subunits)
Figure 5.20 Primary structure of a protein
• Based on amino acid sequence
• Each protein has a unique sequence
• Like the alphabet (letters = aa)
Gly Pro Thr Gly
Thr
+H N
3
Amino acid
subunits
Gly
Amino end
Leu
Seu
Pro Cys Lys
Glu
Met
Val
Lys
Val
Leu
Asp
Ala Val Arg Gly
Ser
Pro
Ala
Glu Lle
Asp
Thr
Lys
Ser
Tyr
Lys Trp
Leu Ala
Gly
lle
Ser
Pro Phe
His Glu
His
Ala
Glu
Ala Thr Phe Val
Val
Asn
Asp
Arg
Ser
Gly Pro
Thr
Tyr
Thr
lle
Ala
Ala
Arg
Leu
Ser Tyr
Ser
Tyr Pro
Leu
Ser
Thr
Ala
Val
Val
Thr
Asn Pro
Lys Glu
c
o
o–
Carboxyl end
Figure 5.20 Secondary structure of a protein
 pleated
sheet
Amino
acid
subunits
H
O
O
H
R
C N
H
C C N
C
N
C
C
R
O H H
O
C
C
R
H
N
O
N
O
C
H C
H
O
R H C
R
H
O C
N
O
C
C
R
N
C
Based on H-bonds
• α-helix
• adjacent polar aa
H
H
R
H
C
C
N
H
C C N
O H H
R
C
H
N HC N H C
H
C
O
R
C
H H
C C N
O
R
C C N
O H H
R
O
H
H
N H C N
C
H
C
O
R
C
C C
O
R
R
O
H
H
N H C N
C
H
C
O
R
H
C
N H C N
H
C
O
H
H
 helix
R H C R
H
O C
N
O
R
R
C
O
N
C
H C
C N
H H
C C N
O
H
R
R
O
H
C
R
N
C
H
H
- β-pleated sheet
- after folding, polar aa become neighbors
and form H-bonds
Figure 5.20 Tertiary structure
• overall globular shape – 3D structure
• each protein has unique 3D shape
• recall carbon sets the 3D shape
• based on 1° structure (aa sequence)
• rearranged the alphabet to get new words
• Disulfide bridge
• 2 cysteine amino acids
• covalent bond
• van der Waals interactions
• hydrophobic interactions
• ionic bonds
• occasional H-bonds
Hydrogen
bond
CH
CH2
H3C
CH3
H3C
CH3
CH
O
H
O
Hydrophobic
interactions and
van der Waals
interactions
OH C
CH2
CH2 S S CH2
Disulfide bridge
O
CH2 NH3+ -O C CH2
Ionic bond
Polypeptide
backbone
Figure 5.20 Quarternary structure
• more than one 3° polypeptide (subunit) needed for
biological activity
• not all proteins have quarternary structure
• # of subunits varies by protein
Polypeptide
chain
Collagen
 Chains
Iron
Heme
 Chains
Hemoglobin
Chapter 5 The Structure and Function of Macromolecules
10. What are the monomers of proteins?
11. How are all amino acids similar?
12. How are amino acids connected?
13. What are the 4 levels of protein structure?
14. How much does sequence (structure) influence function?
-
Sickle cell anemia
Figure 5.21 A single amino acid substitution in a protein
causes sickle-cell disease
Primary
structure
Normal hemoglobin
Val
His
Leu
Glu
Glu
Sickle-cell hemoglobin
Val
His
Leu


Molecules do
not associate
with one
another; each
carries oxygen
Normal cells are
full of individual
hemoglobin
molecules, each
carrying oxygen


Thr
Pro
Val
Glu
...
structure 1 2 3 4 5 6 7
Secondary
 subunit and tertiary
structures
Quaternary Hemoglobin A
structure
Red blood
cell shape
Pro
1 2 3 4 5 6 7
Secondary
and tertiary
structures
Function
Thr
. . . Primary
Quaternary
structure
 subunit




Function
10 m
10 m
Red blood
cell shape
Hemoglobin S
Molecules
interact with
one another to
crystallize into a
fiber, capacity to
carry oxygen is
greatly reduced
Fibers of abnormal
hemoglobin deform
cell into sickle
shape
Chapter 5 The Structure and Function of Macromolecules
10. What are the monomers of proteins?
11. How are all amino acids similar?
12. How are amino acids connected?
13. What are the 4 levels of protein structure?
14. How much does sequence (structure) influence function?
15. What happens to proteins if they get too hot or experience a
change in pH?
Denaturation
Denatured
protein
Normal protein
Renaturation
Chapter 5 The Structure and Function of Macromolecules
10. What are the monomers of proteins?
11. How are all amino acids similar?
12. How are amino acids connected?
13. What are the 4 levels of protein structure?
14. How much does sequence (structure) influence function?
15. What happens to proteins if they get too hot or experience a
change in pH?
16. What do proteins do?
Table 5.1 Protein function
↓
Chapter 5 The Structure and Function of Macromolecules
10. What are the monomers of proteins?
11. How are all amino acids similar?
12. How are amino acids connected?
13. What are the 4 levels of protein structure?
14. How much does sequence (structure) influence function?
15. What happens to proteins if they get too hot or experience a change in
pH?
16. What do proteins do?
17. What are the different types of nucleic acids?
DNA – deoxyribonucleic acid
RNA – ribonucleic acid
- mRNA – messenger
- tRNA – transfer
- rRNA – ribosomal
18. What are the monomers of nucleic acids?
19. What makes up the monomers?
Figure5.26 Components of nucleic acids
Nitrogenous bases
Pyrimidines
5’ end
5’C
NH2
O
Nucleoside
O
Nitrogenous
base
O
O
5’C
O
3’C

C
CH
CH
5’C
O P O
Purines
CH2 O
O
Phosphate 3’C
Pentose
group
sugar
O
NH2
HC
N C C
N
N C
N
H
Adenine
A
(b) Nucleotide
OH
3’ end
(a) Polynucleotide,
or nucleic acid
O
C
C
CH3
HN
C
HN
CH
C
CH
C
C
CH
N
N
O
N
O
O
H
H
H
Cytosine Thymine (in DNA) Uracil (in RNA)
C
U
T
N
3’C
O
HC
N C N
H
Guanine
G
Pentose sugars
5’
HOCH2 O
4
H H
H
CH
N C C
NH
3’ 2’
OH
1’
H
OH H
Deoxyribose (in DNA)
C
NH2
5’
HOCH2 O OH
4
H H 1’
H 3’ 2’ H
OH OH
Ribose (in RNA)
(c) Nucleoside components
Figure 5.27 DNA Double helix
3 end
5 end
G
C
Sugar-phosphate
backbone
G
C
A
T
C
G
A
T
A
T
G
C
A
A
A
Old strands
T
T
A
T
Base pair (joined by
hydrogen bonding)
Nucleotide
about to be
added to a
new strand
3 end
5 end
New
strands
3 end
5 end
5 end
3 end