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CHAPTER 5
THE STRUCTURE AND FUNCTION
OF MACROMOLECULES
A. Most macromolecules are _________
• The four major classes of macromolecules are:
__________________________________________
________________________
• Three of the four classes of macromolecules form
chainlike molecules called __________.
• Polymers consist of many similar or identical building
blocks linked by covalent bonds.
• The repeated units are small molecules called
____________.
• The chemical mechanisms
that cells use to make and
break polymers are similar
for __________ of
macromolecules.
• The __________________
connects monomers.
• ____________disconnects
polymers
Fig. 5.2a
B. Carbohydrates - Fuel and Building Material
• ______________ include both sugars and polymers.
• The simplest carbohydrates are ________________
• ______________ are consist of two
monosaccharides joined by a ____________
reaction.
• _________________ are polymers of
monosaccharides.
B1. Sugars, the smallest carbohydrates serve
as a source of fuel and carbon sources
B.Carbohydrates
• __________________:
• Molecular formulas are some multiple of CH2O.
• Usually names for sugars end in ____
________________
• Have a carbonyl group and multiple________ groups.
• Are a major fuel for cellular work (particularly
glucose)
• function as the raw material for the synthesis of other
monomers, including those of _____________ and
_______________
B.Carbohydrates
• Two monosaccharides can join with a __________
__________ to form a______________ via
________________.
• Sucrose, table sugar, is formed by joining ________and
________ and is the major transport form of sugars in
plants.
Fig 5.5b
B.Carbohydrates
B2. Polysaccharides have _________ and
___________ roles
• Polysaccharides
• Polymers of hundreds to thousands of monosaccharides
joined by _____________linkages.
• An energy storage_____________ that is hydrolyzed as
needed.
• Examples of polysaccharides for fuel storage from glucose
• ___________ (animals only)
• ___________ (plants only)
• ___________- (plants only)
B.Carbohydrates
• One key difference among polysaccharides develops
from 2 possible ______ structures of glucose.
______ - alpha
glucose
monomers.
Only linkage is different
_________ (plant cell wall)beta glucose
monomers
Fig. 5.7b
Fig. 5.7c
B.Carbohydrates
• Polysaccharide strands form ________________ with other
strands.
• Groups of polymers form strong strands, ____________, that
are basic building material for plants (and humans).
Fig. 5.8
• Why can’t mammals digest __________??
B.Carbohydrates
• Mammalian enzymes cannot _________ the beta
linkages in _________.
How can cows digest cellulose
• Cows and termites have symbiotic relationships
with ____________________, allowing them
access to this rich source of energy.
• _________ is _______________polysaccharide, used in the
exoskeletons of ________________ (including insects, spiders,
and crustaceans).
• Chitin is similar to cellulose, except that it contains a nitrogencontaining appendage on each glucose.
C. Lipids
C. ________ - Diverse Hydrophobic Molecules
Lipids
• the exception among macromolecules because they
do not form _____________.
• Little or no affinity for water.
• Why-? Mostly ______________ covalent bonds.
• Lipids are highly diverse in form and function.
•Not strictly polymers, but assembled by
______________ reactions.
C1. Fats store large amounts of energy
C. Lipids
• A ____contains________ and _____________.
• __________ - a three carbon skeleton with a
_________ group attached to each.
Fig. 5.10a
Fig. 5-11
___________ – a carboxyl
group attached to a long
carbon skeleton, often 16 to 18
carbons long (very
______________).
In a fat, _______________ an _____________,
creating a ________________.
C. Lipids
Fig. 5.11b
The Fatty Acid
chains can be
the same or
different
• If one or more carbon-carbon
•If no carbon-carbon
double bonds, then the molecule
double bonds, then the molecule
is an ____________________
is a ___________________.
Fig. 5.12a
Fig. 5.12b
• ___________fats.
C. Lipids
• Most animal fats
• Solid at room temperature.
• Contribute to __________________ (atherosclerosis)
through plaque deposits.
• _______________ fats.
• Plant and fish fats, known as oils,
• Liquid are room temperature.
• The _______ provided by the ____________ prevent
the molecules from packing tightly together.
C. Lipids
• The major function of fats is ________________.
• A gram of fat stores more than ______ as much energy as
a gram of a polysaccharide.
• Plants use ________ for energy storage when mobility is
not a concern but use _______when dispersal and
packing is important, as in seeds.
• Mammals store fats as long-term energy reserves in
____________ cells.
• Other functions- ___________ vital organs and
________________.
C. Lipids
C2. Phospholipids are major components of
cell membranes
• ____________ = a fat
with _____ fatty acids
attached to _________
plus a ____________
group at the third
position.
Hydrophilic head
• Additional smaller
groups may be attached
to the __________
group.
Hydrophobic tail
Fig. 5-13
C. Lipids
• A cell surface contains
________________
arranged as a _______
• hydrophilic heads on the
outside
• hydrophobic tails form
the core
Fig. 5.14
C. Lipids
C3. Steroids include cholesterol and certain
hormones
• Steroids are_______ with a carbon skeleton
consisting of four fused carbon _____.
• Different steroids are created by varying __________
groups attached to the rings.
• ____________
• component in animal cell
membranes.
• precursor of all other _______
(including hormones)
Fig. 5.15
• high levels in the blood may
contribute to ___________
disease.
D. Proteins
D. Proteins
• Functions include structural support, storage, transport of
other substances, intercellular signaling, movement, and
defense against foreign substances.
Humans have ________________ of different proteins,
each with their own _______ and ____________.
• All protein polymers are constructed from the same
set of __ monomers, called _______________.
• Polymers of proteins are called _____________.
• A protein = one or more polypeptides folded and
coiled into a specific _____________.
D. Proteins
D1. A polypeptide is a polymer of amino
acids connected in a specific sequence
• _____________ consist of four components attached
to a central carbon, the ______________.
1. ______________
4. ________
__________
2. _______________
3. _______________
(or side chain).
Differences in _________
produce the ___ different
amino acids.
R
D. Proteins
• One group of amino acids has ________, ________ R groups.
Rule of
thumb- If
R= only
CH3
groups,
then
_________
Fig. 5.17a
• Another group of amino acids has ______R groups, making them ____________.
Rule of
thumb- If
R has -OH
or =O
groups,
then _____
D. Proteins
• The last group of amino acids includes those with
functional groups that are__________ (ionized) at
cellular pH.
• Some R groups are bases, others are acids.
If R has _____. then _____
Fig. 5.17c
If R has ___ then ______
D. Proteins
• Amino acids are joined in a __________________
• The resulting _________ bond is called a ___________.
Fig. 5.18
D2. A protein’s function depends on its
specific conformation
D. Proteins
• The order of amino acids determines the threedimensional conformation, hence the _________.
• The function of a protein is an ______________________
resulting from its specific molecular order.
• Three levels of structure: ___________________
____________and ___________________
Fig. 5.19
• The_________ structure
of a protein is its unique
_________ of amino
acids.
• Sickle cell disease, abnormal
hemoglobins, is due to a single
__________ substitution.
Normal
Sickle cell
D. Proteins
D. Proteins
• The ____________ structure -hydrogen bonds at
regular intervals along the polypeptide backbone.
• Typical shapes
-_____ (an alpha
helix)
-_____ (beta pleated
sheets).
Not in text
D. Proteins
• ________ structure - determined by interactions
among between ________ and
the___________backbone.
1. _________ bonds
4. _____________- strong
covalent bonds that form
between the sulfhydryl groups
(SH) of cysteine monomers,
stabilize the structure.
2. ___________
interactions
3. _______
bonds
Page 83
D. Proteins
• ______________ structure results from the
aggregation of ____________ polypeptide subunits.
• ___________- fibrous protein of three polypeptides that
are supercoiled like a rope.
• _____________- a
globular protein
with ____ copies
of _____kinds
of polypeptides.
Collagen
Hemaglobin
Page 83
D. Proteins
Review of protein structure
D. Proteins
• Alterations in ______________________________,
or other factors can unravel or __________ a protein.
Disrupt the hydrogen bonds, ionic bonds, and disulfide
bridges that maintain the protein’s shape.
• Some proteins can return to their functional shape
after ___________________, but others cannot.
Fig. 5-22
• The folding of many proteins is protected by
_________________ proteins.
Fig. 5.23
D. Proteins
E. Nucleic Acids
E. Nucleic acids store and transmit
hereditary information
• A gene consists of regions of
DNA, a polymer of ______
____________
• Two types of nucleic acids:
_________________ (RNA)
and _________________
(DNA).
• DNA provides direction for its
own replication.
• DNA makes____ makes _____.
• DNA is the basis of inheritance
• One gene synthesizes one RNA
Fig. 5-25
E. Nucleic Acids
______components in nucleic acids1.____
DNA –__ at the “2” carbon
RNA –___ at the “2” carbon
3. ____
2. _____________
Fig. 5.26c
Fig. 5.26 a and b
E. Nucleic Acids
Three components in nucleic acidsTwo classes of bases
1. Base
Fig. 5.26c
Polynucleotides are connected by
_________________________________.
E. Nucleic Acids
E21. Inheritance is based on replication of
the DNA double helix
• An RNA molecule is single _____________ chain.
• DNA molecules have _____ polynucleotide strands
that spiral around an imaginary axis to form a
__________________.
• The ______________ was first proposed as the structure
of DNA in 1953 by James Watson and Francis Crick.
E. Nucleic Acids
• The _______________ backbones of the two
polynucleotides are on the outside of the helix.
• Pairs of____________
_______, one from each
strand, connect the
polynucleotide chains
with hydrogen bonds.
• Most DNA molecules
have thousands to
millions of base pairs.
Fig. 5.27
E. Nucleic Acids
• Because of their shapes, only some bases are
compatible with each other.
• Adenine (A) always pairs with ______________ and
guanine (G) with _____________
• if we know the sequence of bases on one strand, we
know the sequence on the opposite strand.
• The two strands are _________________.
• Each strand is copied into to make two identical
__________ of the original double-stranded DNA
molecule.
• The copies are then distributed to the
_________________ cells.
E. Nucleic Acids
4. We can use DNA and proteins as tape
measures of_____________
• Genes (___) and their products (_________)
document the hereditary background of an
organism.
• Because DNA molecules are passed from parents to
offspring, __________ have greater similarity than
do ____________ individuals of the same species.
• This argument can be extended to develop a
molecular ________________ between species.
E. Nucleic Acids
• In theory, two species that ________ to be closelyrelated based on fossil and molecular evidence
should also be more similar in DNA and protein
sequences than are _____________ related species.
• In fact, the sequence of amino acids in hemoglobin
molecules differ by only _______________ between
humans and gorilla.
• More distantly related species have more differences.
E. Nucleic Acids