Macromolecules
1
Organic Compounds
• Compounds that contain CARBON
are called organic.
• Macromolecules are large organic
molecules.
2
Carbon (C)
• Carbon has 4 electrons in outer
shell.
• Carbon can form covalent bonds
with as many as 4 other atoms
(elements).
• Usually with C, H, O or N.
• Example:
CH4(methane)
3
Carbon is a Versatile
Atom
• It has 4
electrons in an
outer shell that
holds eight
Carbon can
share its
electrons with
other atoms to
form up to four
covalent bonds
4
Macromolecules
• Large organic molecules.
• Also called POLYMERS.
• Made up of smaller “building blocks”
called MONOMERS.
• Examples:
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic acids (DNA and RNA)
5
Question:
How Are
Macromolecules
Formed?
6
Answer: Dehydration Synthesis
• Also called “condensation reaction”
• Forms polymers by combining
monomers by “removing water”.
HO
H
HO
H
H2O
HO
H
7
Question:
How are
Macromolecules
separated or
digested?
8
Answer: Hydrolysis
• Separates monomers by “adding
water”
HO
H
H2O
HO
H
HO
H
9
Carbohydrates
10
Carbohydrates
• Small sugar molecules to large
sugar molecules.
• Examples:
A. monosaccharide
B. disaccharide
C. polysaccharide
11
Carbohydrates
• Carbohydrates
include:
• Small sugar
molecules in soft
drinks
• Long starch
molecules in pasta
and potatoes
12
Carbohydrates
Monosaccharide: one sugar unit
Examples:
glucose
glucose (C6H12O6)
deoxyribose
ribose
Fructose
Galactose
13
Monosaccharides:
• Called simple
sugars
Include glucose,
fructose, & galactose
Have the same
chemical, but
different structural
formulas
C6H12O6
14
• Glucose &
fructose are
isomers b/c
their
structures
are
different,
but their
chemical
formulas are
the same
Isomers
15
Carbohydrates
Disaccharide: two sugar unit
Examples:
– Sucrose (glucose+fructose)
– Lactose (glucose+galactose)
– Maltose (glucose+glucose)
glucose
glucose
16
Carbohydrates
Polysaccharide: many sugar units
Examples: starch (bread, potatoes)
glycogen (beef muscle)
cellulose (lettuce, corn)
glucose
glucose
glucose
glucose
cellulose
glucose
glucose
glucose
glucose
17
Sugars in Water
• Simple sugars and double sugars
dissolve readily in water
WATER
MOLECULE
They are
hydrophilic,
or “waterloving”
-OH groups
make them
water soluble
SUGAR
MOLECULE
18
Proteins
19
Proteins (Polypeptides)
• Amino acids (20 different kinds of aa)
bonded together by peptide bonds
(polypeptides).
• Six functions of proteins:
1. Storage:
albumin (egg white)
2. Transport:
hemoglobin
3. Regulatory:
hormones
4. Movement:
muscles
5. Structural:
membranes, hair, nails
6. Enzymes:
cellular reactions
20
20 Amino Acid Monomers
21
Structure of Amino Acids
• Amino acids have a Amino
group
central carbon with
4 things boded to it:
Carboxyl
group
R group
Amino group –NH2
Carboxyl group -COOH
Hydrogen
Side group
-H
-R
Side
groups
Serine-hydrophillic
Leucine -hydrophobic
22
Linking Amino Acids
Carboxyl
• Cells link amino
acids together toAmino
Side
make proteins
The process is
called dehydration
synthesis
Peptide bonds
form to hold the
amino acids
together
Group
Dehydration
Synthesis
Peptide Bond
23
Proteins as Enzymes
• Many proteins act as biological catalysts
or enzymes
Thousands of different enzymes exist
in the body
Enzymes control the rate of chemical
reactions by weakening bonds, thus
lowering the amount of activation
energy needed for the reaction
24
Enzymes
Enzymes are globular proteins.
Their folded conformation
creates an area known as the
active site.
The nature and arrangement of
amino acids in the active site
make it specific for only one
type of substrate.
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Enzyme + Substrate = Product
26
How the Enzyme Works
Enzymes
are
reusable!!!
Active site
changes
SHAPE
Called
INDUCED
FIT
27
Denaturating Proteins
Changes in temperature & pH can
denature (unfold) a protein so it no
longer works
Cooking denatures
protein in eggs
Milk protein separates into
curds & whey when it
denatures
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Lipids
29
Lipids
• General term for compounds which are
not soluble in water.
• Remember: “stores the most energy”
• Examples: 1. Fats
2. Phospholipids
3. Oils
4. Waxes
5. Steroid hormones
6. Triglycerides
30
Lipids
• Lipids are hydrophobic –”water fearing”
Do NOT mix with water
Includes
fats,
waxes,
steroids,
& oils
FAT MOLECULE
31
Lipids
Six functions of lipids:
1. Long term energy storage
2. Protection against heat loss
(insulation)
3. Protection against physical shock
4. Protection against water loss
5. Chemical messengers (hormones)
6. Major component of membranes
(phospholipids)
32
Function of Lipids
• Fats store energy, help to insulate the
body, and cushion and protect organs
33
Lipids
Triglycerides:
composed of 1 glycerol and 3
fatty acids.
H
O
H-C----O C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
O
H-C----O C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
O
fatty acids
H-C----O C-CH -CH -CH -CH
2
2
2
H
glycerol
34
Fatty Acids
There are two kinds of fatty acids you may see
these on food labels:
1. Saturated fatty acids: no double bonds
(bad)
O
saturated C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
2. Unsaturated fatty acids: double bonds
(good)
O
unsaturated C-CH2-CH2-CH2-CH
35
Fats in Organisms
• Most animal fats have a high proportion of
saturated fatty acids & exist as solids at
room temperature (butter, margarine,
shortening)
36
Fats in Organisms
• Most plant oils tend to be low in saturated
fatty acids & exist as liquids at room
temperature (oils)
37
Nucleic
Acids
38
Nucleic acids
• Two types:
a. Deoxyribonucleic acid (DNAdouble helix)
b. Ribonucleic acid (RNA-single
strand)
• Nucleic acids are composed of long
chains of nucleotides linked by
dehydration synthesis.
39
Nucleic acids
• Nucleotides include:
phosphate group
pentose sugar (5-carbon)
nitrogenous bases:
adenine (A)
thymine (T) DNA only
uracil (U) RNA only
cytosine (C)
guanine (G)
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Nucleotide
Phosphate
Group
O
O=P-O
O
5
CH2
O
N
C1
C4
Nitrogenous base
(A, G, C, or T)
Sugar
(deoxyribose)
C3
C2
41
5
DNA
double
helix
O
3
3
O
P
5
O
C
G
1
P
5
3
2
4
4
2
3
1
P
T
5
A
P
3
O
O
P
5
O
3
5
P
42
Concept Map
Section 2-3
Carbon
Compounds
include
Carbohydrates
Lipids
Nucleic acids
Proteins
that consist of
that consist of
that consist of
that consist of
Sugars and
starches
Fats and oils
Nucleotides
Amino Acids
which contain
which contain
Carbon,
hydrogen,
oxygen
Carbon,
hydrogen,
oxygen
which contain
which contain
Carbon,hydrogen,
oxygen, nitrogen,
phosphorus
Carbon,
hydrogen,oxygen,
nitrogen,
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